Truck Lane Restriction Study Final Report

Transcription

1 Truck Lane Restriction Study Final Report North Central Texas Council of Governments

2 What is NCTCOG? The North Central Texas Council of Governments is a voluntary association of cities, counties, school districts, and special districts which was established in January 1966 to assist local governments in planning for common needs, cooperating for mutual benefit, and coordinating for sound regional development. It serves a 16-county metropolitan region centered around the two urban centers of Dallas and Fort Worth. Currently, the Council has 233 members, including 16 counties, 165 cities, 23 independent school districts, and 29 special districts. The area of the region is approximately 12,800 square miles, which is larger than nine states, and the population of the region is over 6.2 million, which is larger than 35 states. NCTCOG's structure is relatively simple; each member government appoints a voting representative from the governing body. These voting representatives make up the General Assembly which annually elects a 15-member Executive Board. The Executive Board is supported by policy development, technical advisory, and study committees, as well as a professional staff of 235. NCTCOG's offices are located in Arlington in the Centerpoint Two Building at 616 Six Flags Drive (approximately one-half mile south of the main entrance to Six Flags Over Texas). North Central Texas Council of Governments P. O. Box 5888 Arlington, Texas (817) NCTCOG's Department of Transportation Since 1974, NCTCOG has served as the Metropolitan Planning Organization (MPO) for transportation for the Dallas-Fort Worth area. NCTCOG's Department of Transportation is responsible for the regional planning process for all modes of transportation. The department provides technical support and staff assistance to the Regional Transportation Council and its technical committees, which compose the MPO policy-making structure. In addition, the department provides technical assistance to the local governments of North Central Texas in planning, coordinating, and implementing transportation decisions. Prepared in cooperation with the Texas Department of Transportation and the U. S. Department of Transportation, the Federal Highway Administration, and the Federal Transit Administration. "The contents of this report reflect the views of the authors who are responsible for the opinions, findings, and conclusions presented herein. The contents do not necessarily reflect the views or policies of the Federal Highway Administration, the Federal Transit Administration, or the Texas Department of Transportation."

3 NCTCOG Executive Board President Director Director Director Oscar Trevino Mike Cantrell Bobbie Mitchell David Dorman Mayor, City of North Richland Hills Commissioner, Dallas County Commissioner, Denton County Mayor, City of Melissa Vice President Director Director General Council Chad Adams Tom Vandergriff Bobby Waddle Jerry Gilmore County Judge, Ellis County County Judge, Tarrant County Mayor Pro Tem, City of DeSoto Executive Director Secretary-Treasurer Director Director R. Michael Eastland John Murphy Linda Koop Becky Miller Mayor Pro Tem, City of Richardson Councilmember, City of Dallas Mayor, City of Carrollton Past President Director Director Wayne Gent Chuck Silcox Ken Shetter County Judge, Kaufman County Councilmember, City of Fort Worth Mayor, City of Burleson Regional Transportation Council Cynthia White, Chair Herbert Gears Rich Morgan Commissioner, Denton County Mayor, City of Irving Citizen Representative, City of Dallas Oscar Trevino, P.E. Vice Chair Paul Geisel John Murphy Mayor, City of North Richland Hills Board Chair Mayor Pro Tem, City of Richardson Fort Worth Transportation Authority Linda Koop, Secretary Mel Neuman Councilmember, City of Dallas Bill Hale, P.E. Mayor, City of Mansfield District Engineer Terri Adkisson Texas Department of Transportation, Mike Nowels Board Member Dallas District Deputy Mayor Pro Tem Dallas Area Rapid Transit City of Lewisville Roger Harmon Bill Blaydes County Judge, Johnson County Ed Oakley Councilmember, City of Dallas Councilmember, City of Dallas Jack Hatchell, P.E. Ron Brown Commissioner, Collin County Chuck Silcox Commissioner, Ellis County Mayor Pro Tem, City of Fort Worth John Heiman, Jr. Dorothy Burton Councilmember, City of Mesquite John Tatum Councilmember, City of Duncanville Citizen Representative, City of Dallas Kathleen Hicks Sheri Capehart Councilmember, City of Fort Worth Maxine Thornton Reese Councilmember, City of Arlington Councilmember, City of Dallas Ron Jensen Maribel Chavez, P.E. Councilmember, City of Grand Prairie Carl Tyson District Engineer Councilmember, City of Euless Texas Department of Transportation, Scott Johnson Fort Worth District Mayor Pro Tem, City of Plano Marti VanRavenswaay Commissioner, Tarrant County Jan Collmer Pete Kamp Board Member Mayor Pro Tem, City of Denton Bill Whitfield Dallas/Fort Worth International Airport Mayor, City of McKinney Linda Koop Wendy Davis Councilmember, City of Dallas B. Glen Whitley Councilmember, City of Fort Worth Commissioner, Tarrant County Kenneth Mayfield Bob Day Commissioner, Dallas County Kathryn Wilemon Mayor, City of Garland Councilmember, City of Arlington Becky Miller Maurine Dickey Mayor, City of Carrollton Michael Morris, P.E. Commissioner, Dallas County Director of Transportation, NCTCOG Jack Miller Charles Emery Vice Chair, North Texas Tollway Authority Board Chair Denton County Transportation Authority Surface Transportation Technical Committee Renee Lamb, Chair

4 ABSTRACT TITLE: Truck Lane Restriction Study Final Report AUTHORS: Mike Sims, AICP Senior Program Manager Greg J. Royster, P.E. Principal Transportation Engineer DATE: October 2006 SUBJECT: SOURCE OF COPIES: Left Lane Truck Restrictions for initial implementation in the Dallas-Fort Worth region Regional Information Center NCTCOG P.O. Box 5888 Arlington, Texas (817) NUMBER OF PAGES: 46 ABSTRACT: This report summarizes the comprehensive effort of implementing left lane truck restrictions on portions of the Dallas-Fort Worth interstate system and measuring their effectiveness under varying enforcement phases.

5 TABLE OF CONTENTS EXECUTIVE SUMMARY... 1 STUDY ORGANIZATION... 3 Texas Truck Lane Restrictions... 4 Regional Truck Lane Restriction Pilot Study... 6 Study Partners... 9 Interstate Highway 20 Test Section Interstate Highway 30 Test Section STUDY FINDINGS Compliance Travel Speeds Access and Egress Safety Public Acceptance Enforcement Air Quality STUDY RECOMMENDATIONS Interstate Highway 20 Recommendations Interstate Highway 30 Recommendations Mobility Plan Policy System Implementation...41

6 ACKNOWLEDGMENTS This Truck Lane Demonstration project was conducted in cooperation with the Texas Department of Transportation, the Texas Transportation Institute, the Dallas County Sheriff s Department, the City of Fort Worth Police Department, the City of Arlington Police Department, FFE Transportation Services, and Lisa Motor Lines. The authors wish to acknowledge the following individuals without whose insight and assistance the successful completion of this project would not have been possible: Darren McDaniel, P.E. Theresa Lopez, P.E. Mark Schluter, P.E. (retired) Roy Parikh, P.E. Mohammad Moabed, P.E. Andy Oberlander, P.E. Richard Cortez, P.E. Scott Cooner, P.E. Ed Pultorak, P.E. Bill Webb TxDOT Austin District, Traffic Operations Division TxDOT Fort Worth District, Transportation Operations Division TxDOT Fort Worth District, Transportation Operations Division TxDOT Fort Worth District, Transportation Operations Division TxDOT Dallas District, Transportation Operations Division TxDOT Dallas District, Transportation Operations Division TxDOT Dallas District, Transportation Operations Division Texas Transportation Institute, Texas A & M University, Arlington Urban Office Texas Transportation Institute, Texas A & M University, Arlington Urban Office (formerly) Texas Motor Transportation Association

7 Executive Summary As the number of large freight trucks on the region s roadway system increases, concerns about how to improve the safety and mobility of truck automobile interactions have also increased. Similar to many other states, the State of Texas has put in place laws that make possible the designation of certain lanes of the roadway system as restricted from use by large freight trucks. The record of success of these restrictions has been a subject of some disagreement as results from studies to date have either shown little or no safety improvements through a decrease in truck-related crashes or a large decrease in all collisions during a period of new truck lane restrictions and greatly increased police enforcement of both the truck lane restrictions and standard traffic laws. The Mayors of Dallas, Grand Prairie, Arlington and Fort Worth requested that the Texas Department of Transportation initiate a restriction barring trucks from the far left lane of Interstate Highway 30 from the eastern side of Dallas to the western side of Fort Worth. The Texas Department of Transportation requested that the Regional Transportation Council take the lead in coordinating an initial study of the facility. Due to the lack of a comprehensive study on the subject to date and the lack of any existing truck lane restrictions in the region, this Truck Lane Restriction Pilot Study was initiated as a partnership between the Texas Department of Transportation and the North Central Texas Council of Governments. In order to develop a more detailed understanding of the impact of truck lane restrictions on traffic operations, a study design including two very different facilities and four distinct study phases was established. Interstate Highway 20 (I.H. 20) from Interstate Highway 45 (I.H. 45) to Cedar Ridge Road in Dallas County and Interstate Highway 30 (I.H. 30) from Collins Street to Hulen Street in Tarrant County were selected. The I.H. 20 section is a suburban bypass which serves as a major truck route through the region, including 10% truck traffic. The I.H. 30 section bisects central Fort Worth and carries a more moderate 4% truck traffic. The study design included the following four phases: Phase 1: Base conditions Phase 2: Increased enforcement Phase 3: Truck lane restrictions and increased enforcement Phase 4: Truck lane restrictions 1

8 The Dallas County Sheriff s Office, the Arlington Police Department, and the Fort Worth Police Department increased standard enforcement levels in Phases 2 and 3. This included both increases in standard traffic patrol levels and commercial truck inspection units. The Texas Department of Transportation installed No Trucks Left Lane signs throughout the two corridors at the beginning of Phase 3. This was done in conjunction with a large media outreach effort which included numerous local broadcast news stories and coverage on national trucking radio shows. These signs were in place throughout Phase 4 and have remained in place. A variety of data was collected as part of the study to provide a well-rounded understanding of the impacts of the truck lane restrictions and enforcement in the various phases. This includes data collected from the following sources: Police and Sheriff crash records On-site Intelligent Transportation System monitoring devices Mobile video cameras Automated traffic count recording devices In-cab freight truck video collection Public surveys This data was combined and evaluated to provide answers to the following questions: Do truck drivers comply with the No Trucks Left Lane signage? Do truck lane restrictions have a positive effect on travel speeds? Do truck lane restrictions allow normal entering and exiting of freeways? Did the rate of crashes decrease? Is the general public accepting of the truck lane restrictions? Are truck lane restrictions effective without added enforcement? Do truck lane restrictions have a positive air quality impact? The answer to each of these questions is yes. Truck lane restrictions, as applied in the Study, are beneficial. Compliance rates were as high as 99%. The left lane travel speed increased by approximately one mile per hour. Motorists were not blocked by a wall of trucks from moving to or from an access road. The rate of crashes, measured in terms of total crashes per day per 1,000,000 vehicle miles traveled in dry weather conditions, decreased from 0.18 to 0.04 on I.H. 20 and from 0.55 to 0.43 on I.H

9 The general public was enthusiastic in supporting the lane restrictions. Large corporate trucking firms were generally in favor of or not against the lane restrictions. However, local owner/operators of individual freight trucks were not in favor of the lane restrictions. Two additional conclusions related to safety and air quality come directly from the high compliance rate with the truck lane restrictions during Phase 4, the period without enforcement. First, as the safety data showed improvements even without added enforcement, budgeting for enforcement increases over an extended period is not necessary to achieve a safety benefit. Truck lane restrictions were effective without enforcement. Second, because the compliance rate was high, it is clear that trucks shift from the left to the center and right lanes. Typical center and right lane speeds are lower than left lane speeds. Because large freight trucks emit higher levels of pollutants at higher speeds, reducing the speed of some of the trucks (those moving from the left lane to the center or right lane) reduces the emission levels on highways with a truck lane restriction. The estimated daily air quality benefit of the truck lane restrictions in this pilot study was pounds of Nitrogen Oxides (NOx) per day. The summary recommendations of this study are: 1. Keep the current signs in place. 2. Develop a plan for a system of truck lane restricted roadways. 3. Expand the use of truck lane restrictions. The Regional Transportation Council will continue to monitor the safety and operational record of the current truck lane restrictions in the region and will work with the Texas Department of Transportation to work towards the implementation of specific truck lane restrictions in the future. STUDY ORGANIZATION The Truck Lane Restriction Pilot Study addresses the effectiveness of the implementation of a new operating rule for two sections of Interstate Highway in the Dallas-Fort Worth region. This publication summarizes the findings of a complete report on the Truck Lane Restriction Project developed by Wilbur Smith Associates on behalf of the North Central Texas Council of Governments. The concept of a truck lane restriction is to improve safety and mobility on the 3

10 roadway system by providing additional guidance to the interaction of two classes of vehicles with very different operating characteristics. In the State of Texas, freight trucks may legally be up to 180 feet long and weigh up to 80,000 pounds when fully loaded. In contrast, a Hummer carrying a family of five and groceries weighs about 9,000 pounds. A Toyota Prius and its driver weigh about 3,000 pounds. The time and space necessary for acceleration, deceleration, turning, lane changes, and evasive maneuvers in a large freight truck are dramatically different than the time and space necessary in any automobile. Those differences in operating characteristics contribute to generating roadway conflicts and fatalities. Of the nearly 4,000 fatalities on Texas roads each year, 300 to 400 are fatalities involving a large commercial truck. Texas Department of Public Safety records show that 68% of accidents involving trucks are due to the driver of the automobile. The Texas Motor Transportation Association recently released national data showing similar results; up to 70% of crashes between large trucks and automobiles are due to an error by the driver of the automobile. Crashes or near crashes resulting from poor interaction between the two vehicle classes are more common and more difficult to quantify. Truck lane restrictions are an operational tool aimed at alleviating these problems by limiting the interaction between the two classes of vehicles. Texas Truck Lane Restrictions Within the State of Texas there are currently 181 miles of truck lane restrictions. Truck lane restrictions are active in Dallas, Tarrant, Harris, Bexar, Hayes, Travis, and Williamson Counties. Since the late 1990 s, the Texas Department of Transportation (TxDOT) has maintained a policy favorable to the establishment of truck lane restrictions on major Texas truck routes. In May of 1997, State law was enacted providing a local initiative process for establishing truck lane restrictions. This was targeted toward controlled access facilities with a minimum of three through-lanes in each direction. In this legislation, restrictions were limited to only TxDOT maintained facilities, in the peak periods on weekdays, and limited trucks to only two lanes. A traffic study and approval by the Texas Transportation Commission were required prior to posting a truck lane restriction. 4

11 Initially, this limited authority was only applied to a single facility in Houston, Interstate Highway 10 (I.H. 10). Based on the public release of an examination of that facility by the City of Houston Police Department and the Texas Transportation Institute, truck lane restrictions began to gain favor in the State and, in May 2003, additional legislation was passed to support the ability to pursue truck lane restrictions in the State of Texas. The current rules for truck lane restrictions in the State of Texas, as established by the legislature and applied by TxDOT, allow considerable opportunities for developing new truck lane restrictions. Counties, groups of municipalities, or TxDOT can establish truck lane restrictions by conducting a traffic study and requesting approval from the Texas Transportation Commission. Facilities must be controlled-access roadways with a minimum of three travel lanes in each direction and trucks may be restricted to two or more lanes. Lane restrictions allow a truck to utilize the restricted lane to pass, exit, or enter the roadway. Common terminology used to describe truck lane restrictions refers to the lane that trucks are not permitted to use for through movements. For instance, Houston s restriction of trucks from using the left lane on I.H. 10 is commonly termed a left lane truck restriction. It is important to note, however, that in terms of Section of the Transportation Code, such a restriction is actually referring to the fact that trucks are restricted to use only the two rightmost lanes of a three-lane facility. Within this report, the common terminology will be preserved and used. Thus, a left lane truck restriction is a restriction on trucks such that they cannot use the leftmost lane of a three-lane facility for normal through movements. Similarly, a right lane truck restriction is a restriction on trucks such that they cannot use the rightmost lane of a three-lane facility for normal through movements. For facilities with four lanes, the implication of Section of the Transportation Code is that trucks are restricted to using the rightmost three lanes, but may be restricted to using only two lanes of the facility, depending on the local conditions. Finally, the term trucks is used to describe vehicles with three or more axles, excluding buses. This definition evolved out of truck lane restriction implementation experience along I.H.10 in Houston, where there was room for misinterpretation of what vehicles were actually referred to when trucks were restricted from using the left lane. Identifying trucks as vehicles (single unit or combination units) with three or more axles is consistent with State Legislation and, 5

12 Statewide, the issue of what qualifies as a truck for the restricted vehicle classification is clear to commercial vehicle operators. Regional Truck Lane Restriction Pilot Study The Mayors of Dallas, Grand Prairie, Arlington, and Fort Worth requested that the Texas Department of Transportation (TxDOT) initiate a restriction barring trucks from the far left lane of Interstate Highway 30 (I.H. 30) from the eastern side of Dallas to the western side of Fort Worth. TxDOT requested that the Regional Transportation Council take the lead in coordinating an initial study of the facility. Due to the lack of a comprehensive study on the subject to date and the lack of any existing truck lane restrictions in the region, this Truck Lane Restriction Pilot Study was initiated as a partnership between TxDOT and the North Central Texas Council of Governments (NCTCOG). In order to develop a more detailed understanding of the impact of truck lane restrictions on traffic operations, a study design including two very different facilities and four distinct study phases was established. Interstate Highway 20 (I.H. 20) from Interstate Highway 45 (I.H. 45) to Cedar Ridge Road in Dallas County and Interstate Highway 30 (I.H. 30) from Collins Street to Hulen Street in Tarrant County were selected. The I.H. 20 section is a suburban bypass which serves as a major truck route through the region, including 10% truck traffic. The I.H. 30 section bisects central Fort Worth and carries a more moderate 4% truck traffic. As shown in Exhibit 1, Regional Map, the Study limits are consistent with the Truck Demonstration Corridors approved as part of Mobility 2025: The Metropolitan Transportation Plan, Amended April

13 Exhibit 1: Regional Map Mobility 2025: The Metropolitan Transportation Plan, Amended April 2005!"d$ Kª Ii Truck Lane Demonstration Corridor Project Fort Worth District: I.H 30 corridor, I.H. 820(west) to Dallas/Tarrant County line %&n( %&m( Am Dallas District: I.H. 20 corridor, Dallas/Tarrant County line to I.H. 635/I.H. 30 interchange AÙ!"a$ AÃ Ad K In Am %&l( Am %&l(!"c$ K Hulen Street (Fort Worth) A¼ to Collins Street?b (Arlington) Am %&n( A½ AÏ Aî "d %&k( Cedar Ridge (Duncanville) to IH 45 (Dallas) %&m(!"a$!"h$ %&k(?b!"c$ Im!"a$ Kx The Truck Lane Demonstration Corridor project is a regional pilot program to determine and compare the feasibility, impacts, and effectiveness of: 1) Restricting trucks to operating only in certain lanes in the corridor 2) Providing exclusive dedicated truck lanes through the corridors and on adjoining access/egress lanes and ramps Results will be implemented as applicable to specific corridors region wide. All freeway/tollway corridors require additional study for capacity, geometric, and safety improvements related to truck operations. Ie K North Central Texas Council of Governments Transportation The study design included the following four phases: Phase 1: Base conditions; no truck lane restrictions with standard enforcement August and September 2005 Phase 2: Increased enforcement and no truck lane restrictions October 2005 Phase 3: Truck lane restrictions and increased enforcement Non-holiday weeks during November and December 2005 Phase 4: Truck lane restrictions with standard enforcement January

14 The Dallas County Sheriff s Office, the Arlington Police Department, and the Fort Worth Police Department provided increases to standard enforcement levels in Phases 2 and 3. This included both increases in standard traffic patrol levels and in commercial truck inspection units. TxDOT installed No Trucks Left Lane signs throughout the two corridors at the beginning of Phase 3. This was done in conjunction with a large media outreach effort which included numerous local broadcast news stories and coverage on national trucking radio shows. These signs were in place throughout Phase 4 and have remained in place. A variety of data was collected as part of the study to provide a well-rounded understanding of the impacts of the truck lane restrictions and enforcement in various phases. This includes data collected from the following sources: Police and Sheriff crash records On-site Intelligent Transportation System monitoring devices Mobile video cameras Automated traffic count recording devices In-cab freight truck video collection ` Public surveys The Regional Transportation Council and the Texas Transportation Commission are the decision-making entities for truck lane restrictions in the Dallas-Fort Worth region. This study was designed to provide the analytical basis for making a series of corridor-specific and regional policy and operational decisions about the use of a truck lane restriction. These decisions include answers to the following questions: 1. Should the signs in place on I.H. 20 and I.H. 30 stay in place? 2. Should highway sections with truck lane restriction signs also receive increased levels of enforcement? 3. Should more highways in the Dallas-Fort Worth region be signed with truck lane restrictions? 4. What rules or procedures should be put in place when maintaining or expanding the truck lane restrictions? 5. Should truck lane restrictions be an air quality improvement strategy? 6. Can a system of effective truck lane restrictions be designed? 8

15 NCTCOG staff also met with a representative from the Texas Motor Transportation Association to incorporate the perspective of the trucking industry into the overall truck lane restriction study effort. The result of this coordination was the concurrence of the pilot study design proposal. This study design reinforces the principle of increasing safety and mobility for all motorists. Study Partners The project included coordination with the Dallas and Fort Worth Districts of the Texas Department of Transportation, the Texas Transportation Institute, the Texas Department of Public Safety, several local governments, and the North Central Texas Council of Governments (NCTCOG). Local governments involved included Dallas County, Tarrant County, and the cities of Fort Worth, Arlington, Dallas, Duncanville, Lancaster, and Hutchins. Major partner contributions are described in the sections that follow. North Central Texas Council of Governments (NCTCOG) NCTCOG staff provided a variety of regional coordination activities to support the project including: Serving as the Contract Manager for the consultant contract and as the overall Project Manager Administering coordination of public outreach meetings, Truck Demonstration Corridor Working Group meetings, and related policy or technical committees or sub-committees of the Regional Transportation Council Archiving of mobile video streams on the truck lane restriction test sections Analyzing previous years of crash and citation monthly data and developing a crash index measuring the number of crashes per Average Annual Daily Traffic (AADT) by vehicle type, by month Evaluating the public s perception of the success of the left lane truck restrictions by conducting a survey Leading coordination with all partners and key impacted stakeholders Developing final documentation in overall study methodology Incorporating study results and long-range planning 9

16 Texas Department of Transportation (TxDOT) TxDOT provided a variety of functions to both oversee the project and implement the lane restrictions including: Publishing Notice of Intent for TxDOT initiated truck restrictions Sponsoring Lane Restriction Public Hearing Executing Texas Transportation Commission Minute Order allowing for test lane restrictions along selected portions of I.H. 20 and I.H. 30 Installing and maintaining appropriate signage with placement on existing structures Installing and maintaining appropriate pavement markings Installing and maintaining cameras (temporary or permanent) used to collect the data consistent with capturing the measures of effectiveness agreed upon by the Project Review Committee Texas Transportation Institute (TTI) TTI has previously performed studies of truck lane restrictions in the State of Texas and they provided support to the project by reviewing and commenting on study elements, sharing lessons learned from other studies, and providing mobile cameras to the study area during the test phases. Local Governments Local governments provided a variety of on-going support operations to the study and to truck lane restrictions including: Passing resolutions supporting a truck lane restriction pilot study on the impacted test sections Dedicating law enforcement units as necessary for enhanced enforcement phases of this project Maintaining enforcement of truck lane restrictions into the future Interstate Highway 20 Test Section Interstate Highway 20 (I.H. 20) from Interstate Highway 45 (I.H. 45) to Cedar Ridge Road in Dallas County was selected as part of the study due to the significance of that portion of I.H. 20 to the trucking industry. The eastern limit of I.H. 45 was chosen as a clear cut-off point on the east side prior to the split between Interstate Highway 635 (I.H. 635) and I.H. 20. One of the 10

17 movements on the I.H. 20 interchange requires truckers to move to the far left lane to pass through the interchange. Therefore, I.H. 45 was selected as a logical terminus. The western limit at Cedar Ridge Road was selected because it is the western most interchange prior to lane configuration and elevation changes that occur due to the adjacent Escarpment in southern Dallas County. The 2005 average daily traffic on I.H. 20 in the test section was approximately 143,000, of which 15,300 are trucks and 127,700 are automobiles. The peak hour Level of Service (LOS) ranges from C to E in this test section. If truck lane restrictions are to be shown as generally applicable to the Dallas-Fort Worth region, I.H. 20 provides a test area to examine the impacts in an area with a uniquely high level of truck traffic. I.H. 20 also serves as a hazardous materials bypass for both Downtown Dallas and Downtown Fort Worth and is part of the federally designated Transuranic Radioactive Waste Cargo system. I.H. 20 has ample locations to test the issue of a high volume of trucks creating the potential wall of trucks in the rightmost lane. The presence of several high volume truck stops along the corridor also allowed the opportunity to identify not only automobile conflicts but truck conflicts as well, entering and exiting the roadway during the truck lane restriction test. Interstate Highway 30 Test Section Interstate Highway 30 (I.H. 30) from Collins Street in Arlington to Hulen Street in Fort Worth was selected as part of the study due to the original request from the four Mayors. The eastern limit of Collins Street was chosen as a clear cut-off point prior to State Highway 360 (S.H. 360) and the Dallas-Tarrant County line. The western limit at Hulen was selected because it is the western edge of a series of high volume right lane merges, entrances, and exits impacted by the activity in and around downtown Fort Worth. Dallas County portions originally requested by the Mayors of Dallas and Grand Prairie were excluded from the study because of construction of main lanes and high occupancy vehicle lanes on I.H. 30. The 2005 average daily traffic on I.H. 30 in the Tarrant County test section was approximately 174,000, of which 7,300 are trucks and 166,700 are automobiles. The peak hour LOS ranges from A to E in this test section. If truck lane restrictions are to be shown as generally applicable to the Dallas-Fort Worth region, I.H. 30 provides a test area to examine the impacts in two different area types with the presence of a moderate level of truck traffic. First, in Fort Worth, truck lane restrictions were examined in combination with the traffic conditions associated with a 11

18 large central business district. Second, in Arlington, truck lane restrictions were examined with the traffic conditions associated with access and egress to Arlington s entertainment area. These conditions are expected to be applicable to the remainder of the Dallas-Fort Worth region. 12

19 STUDY FINDINGS The Truck Lane Restriction Pilot Study was designed to provide empirical findings on several important measures of effectiveness related to truck lane restrictions. These questions are: 1. Do truck drivers comply with the No Trucks Left Lane signage? 2. Do truck lane restrictions have a positive effect on travel speeds? 3. Do truck lane restrictions allow normal entering and exiting of freeways? 4. Did the rate of crashes decrease? 5. Is the general public accepting of the truck lane restrictions? 6. Are truck lane restrictions effective without added enforcement? 7. Do truck lane restrictions have a positive air quality impact? Answers to these questions provide the necessary guidance for regional decision-making. Each question is analyzed in five parts. These include Purpose, Available Data Sources, Key Data for Each Study Phase, Comparison of Phases, and Conclusions. This section provides a summary report for each. In general, the results are positive and indicate both a reason to move forward with additional truck lane restrictions and a need for additional study and caution on certain site-specific issues. Compliance Purpose Do truck drivers comply with the No Trucks Left Lane signage? The answer to this question forms the basis for assessing the remaining questions related to the effectiveness of the truck lane restrictions. If the lane restriction signs or the signs in combination with enforcement induce a change in driver behavior, then some meaningful conclusions may be drawn related to the different study phases. Without a change in driver behavior, it would be wrong to ascribe to any changes between study periods to the truck lane restrictions signs. The purpose of asking and answering this question is to understand the type, magnitude, and direction of change of truck drivers use of the far left-lane. 13

20 Available Data Sources There are several data points that provide some indications of the change in behavior due to the implementation of signs along the route. These include Intelligent Transportation Systems (ITS) data collection, video data collection, and the public survey. The public survey information is purely anecdotal in nature. Of the survey respondents, 69.5% indicated that they felt conditions had greatly or slightly improved. Written responses to the survey in the comments section made it clear that drivers were reacting to a perceived reduction in the number of trucks in the left lane. The video data collection, designed primarily to collect data on traffic conditions along the ramp, provided the same sort of anecdotal impressions that compliance to the signs was taking place. The primary statistical insight on this question, however, comes from the ITS data collection. Key Data for Each Study Phase For I.H. 20, the ITS data was not able to provide readings on the distribution of trucks per lane. The only data available was from video data collection on I.H. 20 at I.H. 35E. For eight separate two hour sessions, from mid-august to mid-september, data on the truck and automobile volume by lane was collected for Phase 1 of the Study. A summary of this data is provided in Exhibit 2. 14

21 Exhibit 2: Lane Distribution of Trucks on I.H. 20 at I.H. 35E in the Peak Period (Phase 1) 100% 90% 80% 25% 25% 24% 16% Truck Percentage (%) 70% 60% 50% 40% 30% 20% 34% 35% 27% 41% 36% 33% 27% 46% R RM LM L 10% 0% 6% 6% 7% 12% EB WB EB WB AM PM For two separate two hour sessions in mid-november, data on the truck and automobile volume by lane was collected for Phase 3 of the Study. A summary of this data is provided in Exhibit 3. 15

22 Exhibit 3: Lane Distribution of Trucks on I.H. 20 at I.H. 35E in the Peak Period (Phase 3) 100% 90% 80% 29% 24% Truck Percentage (%) 70% 60% 50% 40% 30% 38% 39% R RM LM L 20% 32% 36% 10% 0% 0% 1% EB WB EB WB AM PM For I.H. 30, the ITS data was able to read truck distribution by lane. This automated data was collected at four different locations on I.H. 30, 24 hours per day, 7 days per week, at 15 minute intervals in the peak periods and every hour in the off-peak period. While some data was removed or adjusted during the quality control process, the majority of data was usable. While the data shows the left lane is generally not the preferred lane for trucks, the I.H. 820 interchange is a special case in which the truck drivers move left in reaction to site specific geometric issues. A summary of this data for Phase 1 is shown in Exhibit 4. 16

23 Exhibit 4: Lane Distribution of Trucks on I.H. 30 in the Peak Period (Phase 1) Truck Distribution (%) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 4% 14% 10% 16% 25% 26% 24% 37% 45% 45% 40% 53% 66% 55% 60% 44% 60% 27% 27% 18% 21% 24% 8% 13% 14% 13% 11% EB WB EB WB EB WB EB WB R RM M LM L Beach Street Fielder Loop 820 Morrison Location on I.H. 30 Truck Distribution (%) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 4% 14% 10% 16% 25% 26% 24% 37% 45% 45% 40% 53% 66% 55% 60% 44% 60% 27% 27% 18% 21% 24% 8% 13% 14% 13% 11% EB WB EB WB EB WB EB WB R RM M LM L Beach Street Fielder Loop 820 Morrison Location on I.H. 30 A comparable summary of this data for Phase 4 is shown in Exhibit 5. 17

24 Exhibit 5: Lane Distribution of Trucks on I.H. 30 in the Peak Period (Phase 4) 100% Truck Distribution (%) 90% 80% 70% 60% 50% 40% 30% 20% 24% 40% 33% 19% 38% 28% 37% 40% 60% 54% 16% 40% 43% 27% 64% 19% 60% 48% 46% R RM M LM L 10% 0% 21% 15% 5% 3% 2% 7% 3% 5% EB WB EB WB EB WB EB WB Beach Street Fielder Loop 820 Morrison Location on I.H % Truck Distribution (%) 90% 80% 70% 60% 50% 40% 30% 20% 24% 40% 33% 19% 38% 28% 37% 40% 60% 54% 16% 40% 43% 27% 64% 19% 60% 48% 46% R RM M LM L 10% 0% 21% 15% 5% 3% 2% 7% 3% 5% EB WB EB WB EB WB EB WB Beach Street Fielder Loop 820 Morrison Location on I.H

25 Comparison of Phases For I.H. 20, 99.5% of trucks were in the middle and right lanes during Phase 3, (enforcement and truck lane restrictions). Stated differently, after the signs went up, use of the left lane by trucks decreased by 94%. For I.H. 20 at I.H. 35E, Exhibit 6 below shows the eastbound averages of the morning and evening peak periods in each Study Phase. Exhibit 6: I.H. 20 Distribution of Trucks by Lane Comparison Phase Percentage of Trucks in Compliance Rate the Left Lane Phase 1 6.7% N/A Phase 3 0.5% 99.5% The compliance rate without enforcement was 87.6%. With only the lane restriction sign in place, use of the left lane by trucks dropped by 40% from Phase 1 to Phase 4. For I.H. 30, Exhibit 7 shows the average of both peak periods and both directions for the four different monitoring locations along I.H. 30. Exhibit 7: I.H. 30 Distribution of Trucks by Lane Comparison Phase Percentage of Trucks in Compliance Rate the Left Lane Phase % N/A Phase % 87.6% Conclusion The large sample size on I.H. 30 is the preferred data for drawing conclusions about long-term compliance with truck lane restrictions. A compliance rate close to 90% is similar to identified trends in other regions. The drop from 20.5% of trucks traveling in the left lane in Phase 1 to 12.4% of trucks traveling in the left lane in Phase 4 represents a 40% reduction in the trucks in the left lane in the peak period. This reduction is likely to cause other impacts, in travel speeds and safety for example, and is not dependent on enforcement. 19

26 Travel Speeds Purpose Do truck lane restrictions have a positive effect on travel speeds? This answer is a core operational issue. Evidence that the truck lane restrictions create a decrease in the middle or right lane speeds might indicate a problem with vehicles entering or exiting the roadway. Knowing that vehicles did shift from the left lane to the middle and right lanes, observing constant or slight increases in speed would be consistent with a general improvement in operations due to the truck lane restrictions. An additional purpose of this measure is to assist in evaluating the desirability of applying the truck lane restrictions over a larger area. Available Data Sources All the information to answer this question comes from the ITS data collection. This automated data was collected at four different locations on I.H. 20 and I.H. 30, 24 hours per day, 7 days per week, at 15 minute intervals in the peak periods and every hour in the off-peak period during all the phases of the study. The data for average speed is from the data available for the 6:00 a.m. to 8:00 p.m. period each day. While some data was removed or adjusted during the quality control process, the majority of data was usable. Due to the methodology for summarizing the ITS data, only whole number speed averages are reported. Key Data for Each Study Phase The key data for this question is average speed by lane during Phase 1 and Phase 4 of the study. Exhibit 8 shows the average speed data for I.H. 20 during Phases 1 and 4. 20

27 Exhibit 8: Average Speed by Lane for I.H. 20 (Phase 1 and Phase 4) Phase 1 Average Speed (mph) Phase 4 Average Speed (mph) I.H. 20 Lane Bonnie View Left Left Middle Right Middle Right Duncanville Left Left Middle Right Middle Right Hampton Left Left Middle Right Middle Right Houston School Left Left Middle Right Middle Right Note in Exhibits 8 and 9 the consistent pattern of a slightly faster speed in the left lane during Phase 4. Exhibit 9 shows the average speed data for I.H. 30 during Phases 1 and 4. 21

28 Exhibit 9: Average Speed by Lane for I.H. 30 (Phase 1 and Phase 4) Phase 1 Average Speed (mph) Phase 4 Average Speed (mph) I.H.30 Lane Beach Street Left Left Middle Right Middle Right Loop 820 Left Left Middle Middle Right Middle Right Fielder Left Middle Right Morrison Left Middle Right Comparison of Phases To compare the data between phases, the data was aggregated from each of the individual locations. The middle, right middle, and left middle lanes are averaged and reported as middle for each roadway segment. Summary data for I.H. 20 is shown in Exhibit 10. Exhibit 10: I.H. 20 Change in Average Speed by Lane (Phase 1 and Phase 4) Phase 1 Average Speed (mph) Phase 4 Average Speed (mph) Difference Lane Left Middle Right Exhibit 11 shows the change in average speed per lane for I.H

29 Exhibit 11: I.H. 30 Change in Average Speed by Lane (Phase 1 and Phase 4) Phase 1 Average Speed (mph) Phase 4 Average Speed (mph) Lane Left Middle Right Difference Conclusion While the differences are small, they tend to reflect the intuitive result of the change in compliance rates. When slower moving large trucks move from the faster left lane to the middle and right lanes of the roadway, a marginal increase in left lane traffic speeds is possible for the remaining vehicles. A variety of site specific issues impacts speeds and aggregating the data is a useful way to examine the impacts at a regional scale. Exhibit 12 below shows the combined I.H. 30 and I.H. 20 traffic speed changes and the variation by lane from the combined average speed in the middle lane. 23

30 Lane Exhibit 12: Composite Speed Differentials (Phase 4) Overall Increase in Speeds from Phase 1 to Phase 4 (mph) Overall Variation from the Middle lane Speed in Phase mph faster than the middle lane(s) Left Middle N/A Right mph slower than the middle lane(s) The truck lane restrictions do have a positive effect on travel speeds. This overall data supports two specific conclusions. First, truck lane restrictions are consistent with a small overall increase in speed, particularly in the left lane travel speeds. Second, because some trucks shift to slower lanes, the average speed of trucks on the system decreases. Access and Egress Purpose Do truck lane restrictions allow normal entering and exiting of freeways? The purpose of asking this question is to determine if, in benefiting operations in the left lane, truck lane restrictions might also be degrading traffic operations in the right lane or on access or egress ramps or lanes. It would not be an overall benefit to the system to cause an increase in crashes or queue times on a nearby ramp due to new conditions on the main lanes of the roadway. A primary concern at the beginning of the study was the possible presence of a wall of trucks that might prevent or degrade access or egress. A wall of trucks is described as a series of three-axle or more freight trucks traveling one after the other in a lane or lanes in such density as to block the ability of an automobile driver to change lanes through the middle or right lanes on a facility. Available Data Sources Traffic operations were also recorded on video tapes at selected locations throughout the study corridor for the purpose of collecting vehicle count and classification data and for observing vehicle interactions and driver behavior. Van mounted cameras were placed strategically near the ramp junctions to ensure that the ramp and the freeway main lanes, in the merge or diverge areas, were clearly visible. 24

31 Following is the list of video camera locations along I.H. 20 in Dallas County: U.S. Highway 67, I.H. 35E, Lancaster Road, Bonnie View Road, and I.H. 45. Following is the list of video camera locations along I.H. 30 in Tarrant County: Hulen Street, University Drive, U.S. Highway 287, Eastchase Parkway, and Fielder Road. Video data was collected from August 2005 through March 2006 covering Study Phases 1, 3, and 4. Phase 2 data could not be collected due to equipment failures. The cameras recorded operations in peak periods generally from 6:30 a.m. to 8:30 a.m. and from 4:00 p.m. to 6:00 p.m. Video tapes were viewed to count trucks and cars on ramps and rightmost freeway lanes using a mechanical counter. The vehicle counts were aggregated and recorded every 15 minutes. Special observations recorded from viewing the video tapes were categorized into 10 different groups in order to identify and record any unusual driver behavior or traffic incidents. These were classified into the following general categories for analysis: Cars in outside lane blocking entrance/exit ramp Trucks in outside lane blocking entrance/exit ramp Near collisions (no trucks involved) Near collisions (truck involved) Queues on entrance ramp Queues on exit ramp Queues on freeway Trucks in inside lane, not passing Wall of trucks These video observations were also used to manually obtain counts of cars and trucks on ramps and outside freeway lanes. The counts from the video data were used to calculate the average volumes and truck percentages on ramps and right freeway lanes for all locations. A detailed analysis was conducted to see if there was any correlation between the volume to capacity ratio on the ramps, the percentage of trucks in the right freeway lane, and the occurrence of unusual driver behavior based on the data extracted from the video tapes. 25

32 Key Data for Each Study Phase The key data for this phase is the frequency of different incidents in the video data. Exhibit 13 shows the frequency of incidents for I.H. 20. Exhibit 13: I.H. 20 Frequency of Incidents from Video Monitoring I.H. 20 Phase 1 Phase 3 Phase 4 Hours of Observation Cars in outside lane blocking entrance ramp Near collision (no trucks involved) 2 Near collision (truck involved) 4 1 Queue on entrance ramp Queue on exit ramp Queue on freeway 2 Truck in inside lane, not passing 1 3 Truck in outside lane blocking entrance ramp 1 Wall of trucks 6 Total events Events per hour Exhibit 14 shows the frequency of incidents for I.H

33 Exhibit 14: I.H. 30 Frequency of Incidents from Video Monitoring I.H. 30 Phase 1 Phase 3 Phase 4 Hours of Observation Cars in outside lane blocking entrance ramp 1 Near collision (no trucks involved) Near collision (truck involved) Queue on entrance ramp 2 2 Queue on exit ramp 3 Queue on freeway Truck in inside lane, not passing Truck in outside lane blocking entrance ramp Wall of trucks 2 Total events Events per hour Comparison of Phases There was no correlation of incidents based on study phase. The only correlation of incidents seemed to have been the greater likelihood of any incident type during periods where a high volume to capacity ratio was reported in the traffic lanes or ramp. However, it was difficult to find a strong correlation of this in the data. Exhibit 15 shows the incidence of all observations in all phases in terms of the average right lane truck percentage and the volume to capacity ratio on the ramps. 27

34 Exhibit 15: Combined Result of Video Data Analysis Average Right Lane Truck Percentage 25% 20% 15% 10% 5% 0% V/C ratio on Ramp Near collision (no trucks involved). Near collision (truck involved). Queue on exit ramp. Queue on freeway. Truck in inside lane, not passing. Truck in outside lane blocking entrance ramp. Wall of trucks. No Observations. Conclusion While walls of trucks certainly do occur, both I.H. 20 and I.H. 30 currently have LOS low enough that the frequency of these incidents is fairly low. The truck lane restriction in place in the State of Texas with the poorest LOS is I.H. 35 in Downtown Austin. An analysis of the conditions in that facility may provide useful insight on whether or not a facility with both very high levels of congestion and very high levels of trucks generates a higher frequency of these types of incidents. In conclusion, on I.H. 20 and I.H. 30, access to and egress from the roadway was not adversely impacted by the introduction of truck lane restrictions. 28

35 Safety Purpose Did the rate of crashes decrease? Clearly this question is the priority question for assessing the desirability of truck lane restrictions. Without a safety benefit, there is no compelling reason to add an additional regulatory burden to individual freight truck operators using the public roadways. Consistent with the limited temporal and geographic scope of the study, this measure of effectiveness is defined as the number of accidents per day per million vehicle miles traveled, in dry weather conditions. This statistic was generated for each study phase. Available Data Sources The statistics presented in this section combine traffic data from the ITS system collected by TxDOT and processed by NCTCOG, traffic data from the TxDOT permanent traffic control devices, accident data provided by the Texas Department of Public Safety, the Dallas Sheriff s Office, the Arlington Police Department, and the Fort Worth Police Department. The Study period did not offer enough observations of truck lane restrictions in wet weather conditions to include any analysis of that data. Wet weather days were removed from all the data sets. The ITS automated data was collected at four different locations on I.H. 20 and I.H. 30, 24 hours per day, 7 days per week, at 15 minute intervals in the peak periods, and every hour in the off-peak period during all the phases of the study. The data for average daily traffic (ADT) was collected by the automated ITS devices, compared to nearby TxDOT permanent traffic control data for similar time periods, and adjusted by NCTCOG staff to phase specific ADT. The I.H. 20 ADT is from the Houston School Road location. The I.H. 30 ADT is the average of observations at Beach Street, Loop 820, and Morrison Street. Key Data for Each Study Phase The first observation regarding accidents per day in each phase was the finding that in both of the enforcement phases, there were increases in accident reporting. In addition, accident data for Fort Worth for Phase 2 was not available. This makes it difficult to compare the accident data in those phases against the other phases. To concentrate on the question of what will happen in the long-term, when increased enforcement is not sustainable, comparisons between Phase 1 (base conditions) and Phase 4 (lane restrictions without added enforcement) are made. Data is reported in terms of total accidents, including both truck and auto accidents. Exhibits 16 and 17 provide this data for I.H. 20 and I.H. 30 respectively. 29

36 Exhibit 16: Accident Rate Summary for the I.H. 20 Corridor (Phase 1 and Phase 4) Phase Duration Average Daily Traffic Number of Accidents Accidents per Day Accidents per 100,000 Average Daily Traffic Accidents per 1,000,000 Vehicle Miles Traveled Phase 1 60 days 142, Phase 4 27 days 152, Exhibit 17 provides this data for I.H. 30. Exhibit 17: Accident Rate Summary for the I.H. 30 Corridor (Phase 1 and Phase 4) Phase Duration Average Daily Traffic Number of Accidents Accidents per Day Accidents per 100,000 Average Daily Traffic Accidents per 1,000,000 Vehicle Miles Traveled Phase 1 61 days 167, Phase 4 30 days 166, Comparison of Phases Phase 1 and Phase 4 were different in terms of both the number of accidents per day and the rate of accidents per day when weighted by both average daily traffic and vehicle miles traveled. Exhibit 18 shows this summary comparison. 30

37 Exhibit 18: Summary Accident Rate Comparison Comparison I.H. 20 Corridor I.H. 30 Corridor Percentage of Truck Traffic 10% 4% Question: Is there a statistical difference between Phase 1 and Phase 4? Phase 1 Accidents per 1,000,000 Vehicle Miles Traveled Phase 4 Accidents per 1,000,000 Vehicle Miles Traveled Statistical Significance Test Results Statistically 90% confidence interval Not statistically 90% confidence interval Question: Is the difference greater than the historic difference between Aug./Sep. and Jan.? Average Dry Weather Accidents per Month in January Average Dry Weather Accidents per Month in August and September Average Annual Index Between January and the Previous August and September Phase 1 Adjusted by the Index Percentage Change from Adjusted Phase 1 to Phase % % Conclusion The underlying reason for the substantial variation in accident rates between the two facilities is outside of the scope of this study. However, given the differences between the facilities, observing a change in the same direction, and relative magnitude is an interesting result. I.H. 20, which has four lanes throughout the test area, experiences 10% truck traffic and a 64% 31

38 reduction in accidents was documented. I.H. 30, which has three lanes throughout most of the test area, experiences 4% truck traffic and an 11% decrease was documented. A conclusion consistent with the data would be that truck lane restrictions are simply a more meaningful transportation operational tool in corridors with a higher portion of truck traffic. Overall, the results indicate that truck lane restrictions do make the roadways safer. Public Acceptance Purpose Is the general public accepting of the truck lane restrictions? Gauging public acceptance is an important factor in determining the success of a study of this type. Regardless of the conclusions regarding improvements in tangible benefits such as safety, air quality, and mobility, if the general public does not have a sense of goodwill toward a particular project or study it is difficult and sometimes counterproductive to continue implementation of an otherwise good idea. NCTCOG staff designed, distributed, collected, analyzed, and compiled the results of a survey to determine overall public reaction and acceptance of the truck lane restrictions. Available Data Sources The survey was distributed in various fashions to different groups in order to receive the best cross section of population possible. Surveys were directly distributed to elected officials, mailed to residents along the study corridors, given to individuals at public meetings, placed at local truck stops, and made available on NCTCOG s website. Participants were asked to complete the surveys by May 1, 2006, allowing ample time for respondents to judge the effects of truck lane restrictions based on their personal traveling experience. Key Data Overall there were 236 responses received. According to survey results, about 70% of respondents reported an improvement in their driving experience, 14% reported an inferior driving experience, and 16% reported no change. While only 17% of responses received from commercial vehicle drivers were in favor of expanding the truck lane restrictions, a vast majority (80%) of all respondents were in favor of the truck lane restrictions and further expansion. Comparison of Phases Relative differences between the phases were not part of the survey design. 32

39 Conclusion Overall response to the truck lane restrictions was extremely positive. Information gathered from the surveys along with informal staff contact with public officials and residents during the study indicate a strong desire for expansion of the truck lane restrictions. Contact with commercial vehicle operators indicated that, although not generally in favor of the restrictions, a consistent regional approach would be preferred to an ad hoc localized one. These comments and survey responses provide the public support needed to begin examining all corridors within the region for potential truck lane restrictions. Enforcement Purpose Are truck lane restrictions effective without added enforcement? It was originally reported in the Truck Lane Study along I.H. 10 in Houston, Texas, that accidents were reduced dramatically as a result of the lane restrictions. However, during the study period there was, in addition to the lane restrictions, a significantly increased police presence. Since the added enforcement may have contributed to the reduction in accidents during the Houston study, NCTCOG staff found it may be advantageous to separately determine the effects of added enforcement on accident rates within the I.H. 20 and I.H. 30 corridors. Additionally, compliance to the lane restrictions regardless of the level of police presence needed to be determined. Increased enforcement is defined as a 400% increase in police presence over levels normally deployed by the enforcement agencies. Available Data Sources The statistics presented in this section are the same as those used and reported in the above section on safety. The same data sources were used and analyzed in the same manner. In addition, vehicle count data was used to determine the number of trucks in the left lane both before and after the implementation of the truck lane restrictions in order to measure compliance. Key Data for Each Study Phase As described above in the safety section, it was observed that in both of the enforcement phases there were increases in accident reporting. Accident data in the Fort Worth section of I.H. 30 for Phase 2 was not available. To focus on the question of what effect increased enforcement had on accident and compliance rates, data comparisons are made using all 33

40 phases. However, comparisons are not made between Phase 1 and Phase 4 as both phases have the normal enforcement condition. Data is reported in terms of total accidents, including both truck and auto accidents. Comparison of Phases The table below compares accident rates on both corridors between Phases 1 and 2, which added enforcement only, and Phases 3 and 4, which added the lane restrictions and then removed the additional enforcement, respectively. Exhibit 19 shows this comparison. Exhibit 19: Comparison of Accident Rates (per 1 Million VMT) on I.H. 20 and I.H. 30 (Phase 1 NO Added Enforcement vs. Phase 2 Added Enforcement and Phase 4 NO Added Enforcement vs. Phase 3 Added Enforcement) Variable Comparison I.H. 20 Corridor I.H. 30 Corridor Added Enforcement Phase 1 vs. Phase 2 Phase 4 vs. Phase to 0.36 Statistically Different (100% Increase) 0.04 to 0.32 Statistically Different (700% Increase) 0.55 to 0.06 Statistically Different (89% Decrease) 0.43 to 0.75 Statistically Different (74% Increase) In regard to the compliance rate, the charts below show a comparison of compliance with the lane restriction on I.H. 30 with (Phase 3) and without (Phase 4) added enforcement. While there are variations in the lane distribution of trucks, the data shows a reduction of trucks traveling in the left lane after the implementation of the restrictions with and without added enforcement. Exhibits 20a and 20b show this summary comparison. Similar results were observed on the I.H. 20 corridor. 34

41 Exhibit 20a: Comparison of Lane Distribution of Trucks in Peak Hour on I.H. 30 (Phase 1 vs. Phase 3) Cross Road Direction Lane ID L LM M RM R Beach Street EB -3% 4% - 0% -2% WB 0% -1% - 0% 1% Fielder EB WB Data not available in Phase 3 Loop 820 EB -14% - 4% - 10% WB -9% -13% - 11% 12% Morrison EB -1% - -7% - 8% WB -4% - 5% - -1% Exhibit 20b: Comparison of Lane Distribution of Trucks in Peak Hour on I.H. 30 (Phase 1 vs. Phase 4) Cross Road Direction Lane ID L LM M RM R Beach Street EB -5% 6% - 0% -1% WB 2% 0% - -6% 4% Fielder EB -12% - 1% - 12% WB -14% - -1% - 15% Loop 820 EB -16% - 4% - 13% WB -10% -12% - 11% 11% Morrison EB -3% - -6% - 10% WB -6% - 2% - 3% Legend: X X Difference is statistically significant (at 90% confidence level) Difference is not statistically significant (at 90% confidence level) Conclusion Overall, the addition of increased police presence had a minimal, if any, effect on both safety and compliance. Accident rates both increased and decreased between phases in such a manner as to make drawing a decisive conclusion difficult. For example, while crash rates were lower with additional enforcement on the I.H. 20 corridor without the truck lane restrictions, the crash rates were higher with additional enforcement with the restrictions in place. Differences in the compliance rates also did not show a significant difference with an increased police presence. Taking into account that compliance rates are high with or without a higher than normal police presence, and crash rates overall decreased (see safety section above for 35

42 Phase 1 vs. Phase 4 comparison and conclusions) under the same condition, it can be reasonably concluded that truck lane restrictions are effective without the need for additional enforcement. Air Quality Purpose Do truck lane restrictions have a positive air quality impact? As a federally designated ozone nonattainment area under the 8 hour ozone standard, transportation decisions by the Regional Transportation Council are evaluated to determine the potential air quality impacts. Minor operational adjustments to the system of major roadways in the region can have a measurable impact on air quality emissions from the transportation system. The large trucks regulated by truck lane restrictions have a higher level of emissions than a passenger automobile. If the air quality benefits of truck lane restrictions can be documented, use of truck lane restrictions as a regional air quality improvement strategy may be warranted. Available Data Sources The air quality analysis combines several data points. The change in emissions is equal to Phase 4 emissions minus Phase 1 emissions. The relevant air quality statistics are nitrogen oxides (NOx), volatile organic compounds (VOC), and particulate matter (PM). The formula shown below serves as the basis for calculating the before and after conditions related to the truck lane restrictions. Phase Emissions = (Truck VMT * Portion of Trucks in the Left Lane * Truck Emissions Factor at the Left Lane Speed) + (Truck VMT * Portion of Trucks in the Middle Lane(s) * Truck Emissions Factor at the Middle Lane Speed) + (Truck VMT * Portion of Trucks in the Right Lane * Truck Emissions Factor at the Right Lane Speed) + (Auto VMT * Auto Emissions Factor at the Average Roadway Speed) 36

43 For Phase 1, the calculation is completed using the portion of trucks in each lane and each of the emissions factors related to the speeds from the Phase 1 conditions. For Phase 4, the calculation is completed using the portion of trucks in each lane and each of the emissions factors related to the speeds from the Phase 4 conditions. As the compliance section of this report described, automated ITS data on I.H. 30 provides a complete description of the proportion of trucks in each lane in Phase 1 and Phase 4 of the study. I.H. 20 data was not available, thus this emissions analysis is based only on I.H. 30. In order to separate the impact variations in vehicle miles traveled (VMT) from the emissions analysis, a single average annual vehicle miles traveled statistic is used for both phases. The speed data, as described in the speed section of this report, is also taken from the automated ITS data collection. Key Data for Each Study Phase The key data for Phase 1 and Phase 4 are the input statistics used to calculate the change in emissions statistics for each Phase. This data is summarized in Exhibit 21, using the annualized VMT statistics for auto and truck. Exhibit 21: I.H. 30 Air Quality Impacts Input Statistics (Phase 1 and Phase 4) Phase 1 Phase 4 Auto Vehicle Miles Traveled 2,980,596 2,980,596 Average Roadway Speed 66 mph 66 mph Truck Vehicle Miles Traveled 130, ,524 Left Lane Speed 71 mph 72 mph Left Lane Truck Portion 20.5% 12.4% Middle Lane(s) Speed mph mph Middle Lane Truck Portion 59% 59% Right Lane Speed mph mph Right Lane Truck Portion 20.5% 28.8% Exhibit 22 provides the emissions factors used in the calculations. 37

44 Exhibit 22: Emissions Factors (gram per mile)* (Phase 1 and Phase 4) NOx VOC PM2.5 PM10 Autos at MPH Phase 1 Trucks at MPH Trucks at MPH Trucks at MPH Autos at MPH Phase 4 Trucks at MPH Trucks at MPH Trucks at MPH * Emission factors are based on the Environmental Protection Agency (EPA) Mobile 6 modeling results in the DFW area on August 17,

45 Comparison of Phases Based on the data and formula presented, a variety of emissions from each phase may be calculated. Exhibit 23 shows the result of this calculation. Exhibit 23: I.H. 30 Air Quality Emissions Results* (Phase 1 and Phase 4) Phase 1 (grams) Phase 4 (grams) Change (grams) Change (pounds) NOX Emissions (grams) 6.48 * * , VOC Emissions (grams) 1.83 * * PM 2.5 Emissions 8.26 * * (grams) 0 PM 10 Emissions (grams) 1.34 * * Conclusion A reduction of over 61 pounds of Nitrogen Oxide emissions, as shown in the table above, is an air quality benefit that exists for the approximately 18 miles of test section of I.H. 30. The potential application of left lane truck restrictions in the region, of course magnifies the impact that can be made towards meeting federal air quality standards as well as maintaining a health benefit for the over six million people residing in the North Central Texas region. 39

46 STUDY RECOMMENDATIONS Overall, the results of this study were successful and the enhancement and expansion of truck lane restrictions is recommended. Recommendations are provided for Interstate Highway 20, Interstate Highway 30, the Mobility Plan, the Regional System, and Future Implementation. Interstate Highway 20 Recommendations For the Pilot Study section currently in place on I.H. 20 from I.H. 45 to Cedar Ridge Road, the conclusions of this report are as follows: Leave the current signs and truck lane restriction in place. Pursue installation of permanent signs on the left side of roadway as practicable. Continue to monitor compliance, operational, and safety data. Examine opportunities to expand the facility. Interstate Highway 30 Recommendations For the Pilot Study section currently in place on I.H. 30 from Collins Street to Hulen Street, the conclusions of this report are as follows: Leave the current signs and truck lane restriction in place. Pursue installation of permanent signs on the left side of roadway as practicable. Continue to monitor compliance, operational, and safety data. Examine opportunities to expand the facility. Mobility Plan Policy With the completion of this study, the next step to regionalize the results is to establish a Mobility Plan Policy related to truck lane restrictions. Implementation of a regional system of truck lane restrictions will be based on Texas Transportation Commission administration of State Law regarding truck lane restrictions, site specific conditions and traffic operations analysis, and regional policy regarding truck lane restrictions. The recommended policy for the Mobility Plan is shown in Exhibit

47 Exhibit 24: Regional Policy on Truck Lane Restrictions System Implementation As stated in Exhibit 24 above, there are four considerations for developing a regional system. This portion of the report examines each of these. The first question is what portions of the regional controlled access system have three or more lanes. To simplify this analysis, it is assumed that truck lane restrictions would not be in place on segments of the system that are exclusive toll facilities or which are too short or disconnected from the rest of the regional system to be practical at this time. Exhibit 25 shows the results of this analysis for the anticipated 2007 roadway network. 41

48 Exhibit 25: 2007 Regional Freeway Facilities with Three or More Lanes There are approximately 420 centerline miles of roadway in the region meeting this first of four criteria for truck lane restrictions. The second criteria is the level of truck volumes on the regional roadway system. Exhibit 26 shows the current level of truck volumes on the regional roadway system. 42

49 Site and corridor specific conditions are another major consideration in local implementation. Some of these include site specific geometric constraints, construction, interchanges that require a left exit, or limited sections where a three or more lane roadway drops down to two lanes. Each of these potential obstacles needs to be considered in a more detailed study. The only corridor specific constraint for which data is available at a regional scale is congestion. Typical, recurring level of service (LOS) on the test sections in this study range from LOS A to LOS E. Additional study at poor levels of service is needed prior to making the region-wide recommendation to add truck lane restrictions to corridors with everyday LOS F conditions. Exhibit 27 shows congestion levels in the morning peak period. 43

50 Exhibit 27: Morning Peak Period Exhibit 28 shows congestion levels in the afternoon peak period. 44

51 Exhibit 28: Afternoon Peak Period Finally, the potential Statewide truck lane restrictions to be considered include routes to and from the Port of Houston, Mexico, Canada, the Pacific Coast, and the Atlantic Coast. Exhibit 29 provides the recommendations of this report for the next corridors to explore the expansion of truck lane restrictions. 45

52 Exhibit 29: Recommended Truck Lane Restrictions The cost of signing the two facilities in this project was just over $100,000. The I.H. 20 section is miles long and cost $44,025 to implement. The I.H. 30 section is 17.9 miles long and cost $59,159 to implement. The average cost per mile for both was approximately $3,500. For signs alone, a 100 mile system would cost approximately $350,000. Advanced planning will entail selecting, designing, implementation administration, advertising, enforcing, and monitoring of the truck lane restrictions at additional expenses. 46