Vehicle Kilometres Travelled in Calgary

Transcription

1 2010 Vehicle Kilometres Travelled in Calgary Proposed Methodology The City of Calgary Transportation Planning June 2010

2 2

3 Table of Contents 1.0 Summary Background Methodology Objective and Definitions Possible Methods of Calculating VKT Daily Vehicle Kilometres Travelled Definition Primary Roadway Definitions Data Sources Roadway Segment Lengths Data Sources Traffic Volume Data Sources Traffic Volume Data Source for Primary Roadways with less than 10,000 Vehicles per Day Daily VKT Calculation and Analysis Comparison with the Regional Transportation Model Results Annual Vehicle Kilometres Travelled Definition Daily-to-Annual Factor Total Annual VKT per Capita Calculation Conclusion and Recommendations Appendix A Statistical Analysis of Recommended Volumes on Primary Roadways with Traffic Volumes under 10,000 vehicles per day Appendix B Permanent Traffic Counting Station Locations Appendix C Daily-to-Annual Factors Appendix D Average Fuel Prices in Calgary References

4 List of Figures Figure 1. Calgary Transportation Plan 2009: Road and Street Network Figure Flow Map Primary Roadway Network Figure Major Streets Missing Links Figure 4. Double line example from the RoadNet GIS (red line) replaced with a single blue line in the Flow Map database Figure Flow Map Average 24-hour Weekday Traffic Volumes Figure 6. Daily VKT by Roadway Classification Figure 7. Roadway Classification Breakdown Figure 8. RTM Primary Roadway Network Figure 9. Annual VKT in Calgary Figure 10. Annual Vehicle Kilometres Travelled per Capita Figure 11. Population and VKT percentage growth in Calgary since Figure 12. Recommended Value for Skeletal Roads with Traffic Volume under 10,000 Vehicles per Day 29 Figure 13. Recommended Traffic Volume for Major Streets Figure Permanent Traffic Count Station Locations Figure 15. Fuel prices in Calgary since

5 List of Tables Table 1. Annual vehicle kilometres travelled per Capita for Calgary as reported by Kenworthy... 9 Table 2. Recommended Traffic Volumes for Primary Roadways Table Daily VKT Calculation Table Daily VKT Calculation Table Daily VKT Calculation Table Daily VKT Calculation Table Daily VKT Calculation Table RTM Daily Vehicle Kilometres Travelled Table 9. Daily-to-Annual Factor Table 10. Annual Vehicle Kilometres Travelled per Capita Table 11. Average Traffic Volumes for Primary Roadways with Traffic Volumes under 10,000 Vehicles per Day Table 12. Skeletal Roads Average Traffic Volume and Sample Size per Year Table 13. Skeletal Roads Recommended Volume Analysis Table 14. Major Streets Average Traffic Volume and Sample Size per Year Table 15. Major Streets Recommended Volume Analysis Table 16. Daily VKT Calculation using (µ±s) Traffic Volume Variations Table 17. Major Streets Traffic Volume Sensitivity Analysis Table 18. Daily-to-Annual Factor Calculation

6 6

7 1.0 Summary The City of Calgary (Transportation Planning, Transportation Data division) has developed a methodology regarding the calculation of vehicle kilometres travelled (VKT) within Calgary s city limits based on observed traffic volumes. Currently, VKT estimates can be determined from several sources, including: traffic counts; transportation models; surveys; odometer readings. It is important to develop a methodology that can be standardized, is consistent and easy to use nationwide. Estimated VKT (using different sources and/or methodologies) have been used for comparison with other cities or for benchmarking, which can be misleading if a standardized methodology is not used. It is essential to provide a VKT definition with any VKT release, so a number of questions are answered: Which roadways are taken into consideration in terms of roadway classification? Are they private roads or are they owned by the municipal, provincial or federal government? Are they within the city limits? Are average annual daily traffic (AADT) volumes used for the VKT calculation? Are daily or annual VKT estimates being compared? How is the annual VKT estimated? This report will attempt to answer some of these questions, as well as propose a methodology that may be easily adopted by other municipalities. The report will not discuss the factors influencing the VKT value such as: spatial segregation of land uses and consequently trip length; personal income; auto ownership; travel time budget; fuel prices and fuel economy of vehicles ; Travel Demand Measures like telecommuting and flex work time. 7

8 2.0 Background The vehicle kilometres travelled (VKT) indicator is one of the performance indicators that is widely used in literature as a common measure of roadway use. It is used in estimating congestion and can provide a general measure of the level of economic activity in a city. In addition, this indicator is used for transportation greenhouse gas (GHG) emissions and air quality calculations. Approximately 30 per cent of all GHG emissions in Calgary are produced by transportation sector 1. The VKT indicator reflects the link between land use and transportation. Land uses (home, job, school, day care, retail, etc.) that are further away from each other result in longer trip lengths and inevitably 2 lead to more traffic on the streets and more vehicle kilometres travelled. The Municipal Development Plan (MDP) 3 and the Calgary Transportation Plan (CTP) 4 were adopted by Calgary s City Council on September 28, The Transportation Monitoring and Reporting Program is being developed to provide a mechanism through which CTP and MDP goals, objectives and policies are assessed. The progress of achieving these goals, objectives and policies will be reported based on the measurements of indicators that are identified through the mentioned plans, as well as the Plan It Calgary Implementation Plan. However, any one indicator should not be taken in isolation of other indicators, as only a full set of indicators can provide a comprehensive picture in order to make strategic decisions. 5 The Transportation Research Board s Sustainable Transportation Indicators Subcommittee identifies the annual vehicle kilometres travelled (annual VKT) indicator as one of the most important economic indicators. It is also in direct correlation with environmental indicators, such as greenhouse gas emissions and air quality. 6 The Transportation Association of Canada (TAC) conducts a survey on urban transportation indicators every five years. One of those indicators is daily vehicle kilometres travelled by passenger vehicles per capita. Only a few of the surveyed cities reported the values on this indicator, perhaps because it is challenging to report on daily VKT for passenger vehicles only without doing an extensive and therefore 1 Plan It Calgary. Where do we grow from here? Workbook, 2007 < 2 Reid Ewing, Keith Bartholomew, Steve Winkelman, Jerry Walters and Geoffrey Anderson. Urban Development and Climate Change. Journal of Urbanism, November 2008 < 3 City of Calgary. Municipal Development Plan, 2009 < 4 City of Calgary. Calgary Transportation Plan, 2009 < 5 Sustainable Transportation Indicators Subcommittee of the Transportation Research Board (ADD40 [1]). Sustainable transportation Indicators: A Recommended Research Program For Developing Sustainable Transportation Indicators and Data. November 2008 < 6 IBI Group, Transportation Association of Canada. TAC Urban Transportation Indicators Fourth Survey. Draft Final Report. November

9 expensive survey or using a transportation model. Furthermore, those reported values may come from different sources (e.g., travel demand model or observed traffic count data) and the conclusions could be deceiving if those reported values are compared between cities that used different methodologies. For comparison purposes, it is essential to have a consistent and standardized methodology. The analysis of vehicle miles travelled (VMT) and its trends have been done on a regular basis in the U.S. 7 The Federal Highway Administration (FHWA) 8 publishes highway statistics, which contains the sectional lengths for all public roads and vehicle miles travelled by state. Based on state-managed permanent traffic counters, the average annual daily traffic (AADT) is measured and then multiplied by the length of the roadway section to get daily VMT. The VMT for the entire year are calculated by multiplying daily VMT by 365 (days). The methodology used to calculate VMT is similar to the proposed VKT methodology in Calgary. Annual VKT per capita for Calgary was first published in The International Source Book of Automobile 9 Dependence in Cities, by Kenworthy and Laube. It is assumed that the estimates were provided by The City of Calgary, but the original calculations could not be obtained. The values for this indicator are given in the table below. Dr. Kenworthy provided a value for 1996 via . Table 1. Annual vehicle kilometres travelled per Capita for Calgary as reported by Kenworthy Year Annual VKT per capita , , , ,237 7 Robert Puentes, Adie Tomer. The Road Less Traveled: An Analysis of Vehicle Miles Traveled. Brookings Institution. Metropolitan Infrastructure Initiative Number 4. December 2008 < 8 U.S. Department of Transportation. Federal Highway Administration. Policy Information. Travel Monitoring. < 9 Jeffrey Kenworthy, Felix Laube. The International Source Book of Automobile Dependence in Cities, University of Colorado Press,

10 3.0 Methodology Objective and Definitions The objective was to develop a process that measures travel demand over time on an annual basis. The method used to calculate the annual VKT within Calgary s city limits based on readily available, observed data should be: repeatable from year to year using available data; simple and easy to understand; data are cost-effective to collect; data are easily and reliably measurable; VKT estimates are comparable to estimates reported by other cities (assuming the same methodology is used); estimates should not vary radically from year to year due to sampling error; and, allow for future enhancements to improve the quality of the estimates. 3.1 Possible Methods of Calculating VKT The Regional Transportation Model 10 (developed by the Forecasting Division in Transportation Planning) can calculate daily VKT and forecast future years based on the land use and transportation network assumptions. As the model is calibrated using the Household Activity Survey, which is conducted every ten years, and recalibrated using ground counts at five year intervals between surveys, the VKT produced cannot be used for monitoring on an annual basis. Currently Alberta has a voluntary odometer reading program. Every year when a vehicle is registered, one can voluntarily report the odometer reading for that vehicle. In some European countries, odometer reporting is mandatory. In the long-term, the Province of Alberta might request mandatory odometer reporting. However, there are a few caveats with mandatory odometer reporting, as it includes all travel in the city and outside the city (e.g., vacation). Furthermore, there are many company headquarters in Calgary, so for example, a vehicle could be registered in Calgary, but its location is really in Fort McMurray and all VKT could occur in and around Fort McMurray. Therefore, using odometer readings to determine vehicle kilometres travelled in Calgary would not be accurate. Household activity surveys can be used to determine the number of vehicle kilometres travelled per household. However, in order to obtain a sample size large enough to obtain an accurate estimate of VKT many households need to be surveyed and the study becomes extremely expensive. This would not be practical methodology for reporting on a frequent basis. 10 City of Calgary. Transportation Planning. Forecasting division. 10

11 3.2 Daily Vehicle Kilometres Travelled Definition Daily vehicle kilometres travelled are calculated by multiplying the observed 24-hour average annual weekday traffic volumes by the single centre-line length of the primary roadways within city limits only. As part of the definition further clarification is needed: Daily VKT include all weekday travel on Calgary streets by not only Calgarians but also all visitors and commuters from the region. It also includes all commercial travel (passengers and goods) on Calgary roadways. Daily VKT do not include any traffic volumes on the roadways outside of Calgary (e.g., a trip from Airdrie to downtown Calgary would only include the kilometres travelled within the city) nor weekend travel. All primary roadways were included in the calculation regardless of the ownership (e.g., Deerfoot Trail is included in the VKT calculation even though it is owned by the Province of Alberta). It is important to note that the VKT calculation does not include travel on all Calgary roadways. Residential Streets are not used in the VKT calculation because of traffic volume variations throughout the city on these roadways. In addition, the existing traffic count sample on these roadways is too small to make a reliable estimate. Traffic volumes on these roadways could be biased, as the few traffic counts on residential roadways are usually done as part of traffic calming studies, crosswalk warrants or other special studies. Furthermore, in the TAC Urban Transportation Indicators, roadway use was measured on arterials and expressways (or multi-lane highways) only. The method to calculate daily VKT for a segment is to multiply the length of a roadway segment by the volume of traffic on that segment. The formula for the daily VKT on a segment calculation is given below: Daily VKT = Segment length (km) x Volume on that segment (vehicles per day) Primary Roadway Definitions Primary roadways may have different definitions throughout Canada. Generally, they represent roadways with higher capacity and higher traffic volumes. It is important to establish the clear definition nationwide. In Calgary, under the current Calgary Transportation Plan 2009 classification, primary roadways consist of Skeletal Roads, Arterial Streets, Parkways, Urban Boulevards, Neighbourhood Boulevards and Industrial Arterials (Figure 1). 11

12 Skeletal Roads (usually named expressways and freeways) have an emphasis on moving vehicular traffic over great distances. They typically operate at high speeds ( 80 km/h) and have little interaction with adjacent land uses. The access to these roadways is very limited (every 800 m to 3200 m). Skeletal Roads usually form a skeletal grid across the city with approximately three to five kilometres spacing. The average annual daily traffic volume (AADT) is usually high (> 50,000 vehicles per day). In 2008, the AADT on certain segments on Deerfoot Trail was greater than 170,000 vehicles per day. Arterial Streets, Parkways, Urban Boulevards, Neighbourhood Boulevards and Industrial Arterials (further referred as Major Streets in the report) have varying degrees of interaction with adjacent land uses. Open space and natural areas are adjacent to Parkways and Industrial Arterials are located in industrial areas and have a high percentage of truck volumes. Urban and Neighbourhood Boulevards are destinations (mixed-land use developments) with a pedestrian-friendly streetscape and high quality urban design. Arterial Streets provide a direct connection between the communities, to/from major destinations, and they accommodate all modes of transportation. The intersection spacing varies and depends on adjacent land use: from 60 m on Neighbourhood Boulevard to a maximum of 500 m on an Arterial Street. The AADT varies from 10,000 vehicles per day on a smaller Arterial Street to over 50,000 vehicles per day such as on Macleod Trail in Definitions and other information on roadway classification can be found in the Calgary Transportation Plan. Classifying roadways by function (not by name) allows us to define primary roadways that can be compared nationwide. 12

13 Figure 1. Calgary Transportation Plan 2009: Road and Street Network 13

14 3.3 Data Sources Roadway Segment Lengths Data Sources The main source of data is the Flow Map GIS database created by the Transportation Data division 11. This database contains single line lengths roadways in Calgary and a 24-hour average weekday traffic volume on those segments back to As the Flow Map database includes only primary roadway segments with a traffic volume 10,000 vehicles, for the VKT calculation, the database was expanded with all primary roadway segments that have less than 10,000 vehicles per day (examples in Figure 2 and Figure 3). Figure Flow Map Primary Roadway Network Figure Major Streets Missing Links The source for the missing roadway lengths (green line in Figure 3) from the Flow Map database is the ArcGIS RoadNet (future TransNet) layer, maintained by Roads, Traffic division. This database contains a record of the length of roads and streets by roadway classification: Freeways and expressways Major Streets Collector roadways Local roadways 11 City of Calgary. Transportation Planning. Transportation Data division. 14

15 The existing RoadNet GIS layer represents roadways with a median as two lines instead of one centreline. It also includes all ramps as separate lines. The total length of roads and streets could not be used from the RoadNet database as that total contains double-counted line lengths (e.g., Deerfoot Trail has two lines in the RoadNet database). For the VKT calculation, centre-line length is taken only once, as traffic volumes represent volumes in both travel directions. The following example illustrates the difference between the RoadNet and Flow Map layers. Figure 4. Double line example from the RoadNet GIS (red line) replaced with a single blue line in the Flow Map database The roadway lengths for the primary roadways network missing from the Flow Map database are calculated as a difference between the Flow Map layer and a single line from the RoadNet for each year. The difference is shown separately for each roadway classification, for each year in Tables 3 7. The CTP 2009 introduced the new roadway classification (Figure 1). As only the primary roadway network is used for the VKT calculation, there is a need to translate the old roadway classification into the new roadway classifications: Freeways and expressways are Skeletal Roads Major Streets are Arterial Streets, Industrial Arterials, Urban Boulevards, Neighbourhood Boulevards and Parkways This will be done once the new TransNet layer is introduced in Once the GIS TransNet layer is adjusted to reflect the new roadway classifications and has the ability to create a centre line, it will be easier to measure segment lengths in the future. Consequently, the VKT will be easier to calculate. 15

16 3.3.2 Traffic Volume Data Sources The main source for traffic volume data is the Flow Map GIS database. This database uses all of the traffic count data: manual intersection 6-hour traffic counts; short-term automatic 24-hour counts; permanent traffic counting station counts. In general, the Flow Map (an example shown in Figure 5) database includes expressways and freeways, Major Streets, special collectors (such as Elbow Drive) and a few local streets with daily traffic volume greater than 10,000 vehicles per day. The current practice is to exclude roadway segments with less than 10,000 vehicles per day in the database. The volumes are reviewed each year and compared with previous years to ensure they are reasonable. As the Flow Map database represents average daily, weekday traffic volumes, adjustment factors are developed from the permanent traffic counting stations and automatic 24-hour counts. Those adjustment factors are then applied to the six-hour manual counts to represent 24-hour volumes. For more details about the Flow Map database and above-mentioned factors refer to Transportation Data division. 16

17 Figure Flow Map Average 24-hour Weekday Traffic Volumes 17

18 3.3.3 Traffic Volume Data Source for Primary Roadways with less than 10,000 Vehicles per Day For primary roadway segments that are not included in the Flow Map database, the volume is estimated based on the automatic 24-hour traffic counts from previous years. The following table shows the estimated weekday daily traffic volume based on the traffic count database. Only primary roadways with the volumes less than 10,000 vehicles per day are taken into consideration. Transportation Data division maintains the traffic count database. Table 2. Recommended Traffic Volumes for Primary Roadways Roadway classification Skeletal Roads (formerly expressways and freeways) Skeletal Roads 7,000 Major Streets Streets (Arterial Streets, Industrial Arterials, Urban Boulevards, Neighbourhood Boulevards and Parkways) Recommended weekday volume (vehicles/day) 6,200 The statistical analysis of recommended volumes for Skeletal Roads and Major Streets is shown in Appendix A. 3.4 Daily VKT Calculation and Analysis To calculate daily (Weekday 24-hour) VKT for Calgary, a VKT database was created using all of the following sources: Flow Map database roadway network GIS database Transportation Data traffic counts database The VKT database is maintained as both an ESRI GIS file and an Excel spreadsheet file. Using the formula from Section 3.2, daily VKT for the years 2005 through to 2009 are calculated as follows: Table Daily VKT Calculation 18

19 Table Daily VKT Calculation Table Daily VKT Calculation Table Daily VKT Calculation Table Daily VKT Calculation Figure 6 shows a growth of 11 per cent in the daily VKT on Skeletal Roads and almost constant VKT on Major Streets over the five-year period. This is expected, as the largest traffic volumes are observed on the Skeletal Roads, especially Deerfoot Trail where the total traffic volume on all segments within city limits increased by 22 per cent from 2005 to During the same time period, the Skeletal Roads centre-line length increased from 277 km in 2005 to 291 km in 2009 (an increase of 5 per cent), while the centre-line length of Major Streets grew to 560 km in 2009 from 511 km in 2005 (10 per cent increase). 19

20 Figure 6. Daily VKT by Roadway Classification In 2005, the total centre-line length was comprised of 35 per cent Skeletal Roads and 65 per cent Major Streets (Figure 7). Out of all daily vehicle kilometres travelled, 60 per cent occurred on Skeletal Roads. On average, one kilometre of Skeletal Roads centre-line carried more than 47,000 vehicles per day. As shown in Figure 7, the percentage of Skeletal Roads centre-line decreased to 34 per cent in Sixty-one per cent of all daily VKT occurred on Skeletal Roads. On average, one kilometre of Skeletal Roads centre-line carried 50,500 vehicles per day (approximately 6 per cent increase from 2005). During the same period, the average traffic volume per one km of Major Streets decreased from 17,500 vehicles per day in 2005 to 16,700 vehicles per day in

21 Figure 7. Roadway Classification Breakdown Comparison with the Regional Transportation Model Results Daily VKT is one of the outputs of the Regional Transportation Model (RTM). The VKT are calculated by multiplying the number of vehicles on each type of link by the length of the link. For the 2006 base year (R1163), daily VKT for all vehicles (including commercial vehicles) equals 25,220,000. The values shown in Table 8 are rounded to the nearest 10,000 VKT. The main reason daily VKT are higher in the RTM by approximately 8 per cent is that the calculations are based on two different roadway networks. Figure 9 shows the primary roadway network (Skeletal Roads and Major Streets) in the 2006 RTM and Figures 2 and 3 show the 2008 Flow Map primary roadway network and missing links. Table RTM Daily Vehicle Kilometres Travelled Roadway classification 2006 RTM daily VKT Skeletal Roads 16,780,000 Major Streets 8,440,000 Total 25,220,000 It can be concluded that the proposed methodology is in line with the results from the RTM. The results from the proposed methodology are based on the observed traffic volumes and could be used for RTM validation. In the future, an effort will be made to generate identical transportation networks in the Flow Map and the RTM, as per the CTP 2009 roadway classification. 21

22 Figure 8. RTM Primary Roadway Network 3.5 Annual Vehicle Kilometres Travelled Definition Annual vehicle kilometres travelled are calculated by multiplying daily VKT with a daily-toannual conversion factor for each year. As daily VKT represent a 24-hour weekday traffic volume, a daily-to-annual factor is used (not simply 365) to estimate the annual VKT. By using data from the permanent count stations, the daily-to-annual factor takes into account traffic volume variations on weekends and statutory holidays on Calgary roadways. A formula for the annual VKT calculation is given below: Annual VKT = Daily VKT x Daily-to-annual factor Daily-to-Annual Factor The daily-to-annual factor is estimated from permanent traffic count stations. Currently there are 31 permanent traffic count stations located throughout Calgary, mainly on the Skeletal Roads (Figure 14). Only stations that were operational all year (365 days) were taken into consideration for the calculation of this factor. 22

23 The factor varies for each year ( ) and is shown in Table 9 below. A detailed calculation of the daily-to-annual factor can be found in Table 18 in Appendix C. This factor can be easily calculated for each year in the future. Table 9. Daily-to-Annual Factor Year Daily-to-annual factor These factors can be obtained on an annual basis, if permanent count stations are available Total Annual VKT per Capita Calculation To get the annual VKT per capita, annual VKT is divided by population for that particular year (population source: Calgary Civic Census). Table 10. Annual Vehicle Kilometres Travelled per Capita As Figure 9 shows, the annual VKT has a constant increase during the five-year period (12 per cent from 2005 to 2009). However, from 2007 to 2009, the annual VKT increased only by 1 per cent, which may have been in response to rising fuel prices in Calgary (Figure 15 in Appendix D). 23

24 Figure 9. Annual VKT in Calgary Although daily and annual VKT have a steady increase during the five year period, the 2009 annual VKT per capita is almost the same as the 2005 annual VKT per capita. This is mainly due to the population increase of 11 per cent over the five-year time period, but also due to slower increase in annual VKT, especially from 2007 to 2009 (only 1 per cent change). Figure 10 shows the annual VKT per capita over the five-year period. Figure 10. Annual Vehicle Kilometres Travelled per Capita 24

25 Figure 11 shows a relative change in the annual VKT, annual VKT per capita and population growth in relation to the 2005 base year. Annual VKT growth reached plateau in 2007 while annual VKT per capita decreased after 2007 due to steady population increase. Figure 11. Population and VKT percentage growth in Calgary since

26 4.0 Conclusion and Recommendations Vehicle kilometres travelled has been a key transportation indicator for many years. It is commonly used by municipalities, provinces, states and countries to measure roadway usage and to plan for future transportation networks. The VKT correlates directly with urban form and can be used in the strategic decisions that shape future growth of our cities. The proposed methodology has several benefits as noted on the following conclusions and recommendations: Consistent and standardized methodology enables comparison with other cities nationwide. Establishing a standardized and consistent methodology for VKT calculation within Canada allows for benchmarking, so values are comparable between cities. Recommendation: Pursue with TAC and CITE to develop a standardized and consistent methodology for VKT calculation within Canada. Daily VKT and annual VKT per capita can be estimated annually based on the observed traffic volumes in Calgary. By establishing the methodology and calculating the VKT, a good baseline to track the progress towards achieving the MDP/CTP goals and objectives is possible. Daily VKT and annual VKT/capita indicators can be measured over time. Recommendation: Use 2005 as a baseline to track the progress. Consistent and standardized count program provides better quality data. Establishing a consistent and standardized traffic count program for collecting data on all Skeletal Roads and Major Streets in Calgary can provide better quality data and better traffic count coverage within the city. Recommendations: o Based on the Figure 14 in Appendix B, identify other locations and include them in the 2010 automatic 24-hour count program. o It is recommended that traffic counts be obtained on all Skeletal Roads and Major Streets in subsequent years in order to avoid the errors associated with estimating volumes for roadways not on the Flow Map. o Re-create a Flow Map that includes all segments of the Skeletal Roads and Major Streets to reflect Road and Street Network in Figure 1, even though the traffic volume on certain segments is less than 10,000 vehicles per day (now the Flow Map represents all roadways with the volume > 10,000 vehicles per day). This would simplify the Flow Map and the VKT calculation in the future. 26

27 Calculated daily (weekday 24-hour) VKT values are comparable with the RTM values. Observed traffic volume values and modelled values are similar and logical. Observed traffic volume values can be used in the model calibration and validation. Recommendation: o Strengthen the relationship between the Forecasting and Transportation Data divisions. o Use the RTM outputs by trip purpose, such as daily VKT and average trip length at the Area Structure Plan level. GIS based database is easy to maintain and VKT easy to calculate based on the proposed methodology annually. Recommendation: Create a single centre-line attribute in the TransNet layer based on the Flow Map that can be easily imported as necessary. The definition must always be included with any release of either daily or annual VKT. It is necessary to be cautious when comparing the VKT/capita indicator due to differences in calculation methodologies (e.g., different sources, daily vs. annual VKT, which roadway classification taken into calculation). Reporting relative change in the vehicle kilometres travelled values (percentage or direction of change either increase or decrease) are more accurate to report instead of reporting absolute values. The VKT may be impacted by factors not related to the CTP and MDP and their respective implementation plans. New economic opportunities or constraints, such as economic boom or downturn, changes in technology or a massive jump in fuel prices, environmental awareness and social values changes are all unknown variables that can significantly contribute to a VKT increase or decrease. In recent years, we have witnessed how high gasoline prices can motivate drivers to drive less and use other modes of transportation. The three-year VKT review is a part of the regular Monitoring and Reporting Program of the MDP and CTP. 27

28 Appendix A Statistical Analysis of Recommended Volumes on Primary Roadways with Traffic Volumes under 10,000 vehicles per day The recommended volume calculations for Skeletal Roads and Major Streets are derived from the automatic 24-hour counts as the average of the traffic volumes for the period (Table 11). Note that in 2007, no automatic 24-hour counts were performed on Skeletal Roads that had less than 10,000 vehicles per day. Table 11. Average Traffic Volumes for Primary Roadways with Traffic Volumes under 10,000 Vehicles per Day Roadway Classification Year Average Average Traffic Volume on Skeletal Roads 7,513 6,336 6,760 6,432 5,718 8,996 7,549 7,000 Average Traffic Volume on Major Streets 5,659 5,268 5,453 5,717 6,664 6,688 7,161 6,660 6,200 Skeletal Roads Recommended Volume Analysis Based on the automatic, 24-hour counts, an average traffic volume of 7,000 vehicles per day was computed for Skeletal Roads. As the sample size per year is relatively small, a t-test was used for analysis. Figure 12 shows the relationship between the average traffic volumes over the period and a recommended volume of 7,000 vehicles per day. Table 12. Skeletal Roads Average Traffic Volume and Sample Size per Year 28

29 10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Average 24-hr Traffic Volume on Skeletal Roads Average Traffic Volume on Skeletal Roads Recommended Value for Skeletal Roads Figure 12. Recommended Value for Skeletal Roads with Traffic Volume under 10,000 Vehicles per Day For the Skeletal Roads, a t-test is used to determine whether the mean (recommended volume) is significantly different from the samples. The t-test formula is used: where T is a t-value, is an average volume, μ (mean) is a recommended volume, S is a standard deviation, and n is a sample size. It is assumed that 19 out of 20 times (α = 5 per cent) the recommended volumes is 7,000 vehicles per day for 2005, 2006 and No counts on Skeletal Roads with less than 10,000 vehicles per day were found for

30 Table 13. Skeletal Roads Recommended Volume Analysis This test shows that there is no statistical evidence to reject the recommended value of 7,000 vehicles per day. It is recommended that traffic counts be obtained on all Skeletal Roads in subsequent years in order to avoid the errors associated with estimating. Based on the statistical analysis, the average traffic volume of 7,000 vehicles per day is the recommended value for the VKT estimate on Skeletal Roads. Major Streets Recommended Volume Analysis Based on the automatic, 24-hour counts (Table 14), the average traffic volume of 6,200 vehicles per day was computed for Major Streets. Figure 13 shows the relationship between the average traffic volumes over the period and a recommended volume of 6,200 vehicles per day. Table 14. Major Streets Average Traffic Volume and Sample Size per Year 30

31 Average 24-hr Traffic Volume for Major Streets 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1, Average Traffic Volume on Major Streets Recommended Value for Major Streets Figure 13. Recommended Traffic Volume for Major Streets Because the sample size 30 for each year, the normal distribution is used to calculate the probability consistent with the Central Limit Theorem: If is the mean of a random sample of size n taken from a population with mean µ and finite variance σ², then the limiting form of the distribution of As n The following table contains the Z-values for the years Sample standard deviation (S) is used, as it is an unbiased estimate of σ (population standard deviation). Higher probability suggests that the recommended value is a reliable estimate. 31

32 Table 15. Major Streets Recommended Volume Analysis Except for 2005, all other years have a high probability of having average traffic volume of 6,200 vehicles per day. Based on the statistical analysis, the average traffic volume of 6,200 vehicles per day is the recommended value for the VKT estimate on Major Streets. Sensitivity Analysis Sensitivity analysis was done to ensure that the recommended value for Major Streets provides a reliable estimate for the VKT calculation. The analysis was done using the 2009 data and assuming traffic volumes variations (µ ± S). The recommended value for Skeletal Roads is assumed unchanged for this analysis. It is recommended that the traffic volumes be measured in the future on all Skeletal Roads. The estimated daily VKT are shown in Table 16. Table 16. Daily VKT Calculation using (µ±s) Traffic Volume Variations 32

33 Table 17 shows that the estimated VKT on Major Streets represent a three to six per cent share of the total VKT on all primary roadways. That share does not make a significant difference in overall VKT calculations. It is proposed that a value of 6,200 vehicles per day remains as a recommended value for Major Streets when a true volume is not available. Table 17. Major Streets Traffic Volume Sensitivity Analysis Recommended volume Volume (µ+s) Volume (µ-s) (µ) Volume (Vehicles/Day) 6,200 8,650 3,750 Estimated VKT on Major 1,013,000 1,413, ,000 Streets with traffic volume under 10,000 vehicles/day Total VKT on all primary 24,019,000 24,419,000 23,619,000 roadways Per cent of estimated VKT on Major Streets (of total VKT on all primary roadways) 4% 6% 3% 33

34 Appendix B Permanent Traffic Counting Station Locations Figure Permanent Traffic Count Station Locations 34

35 Appendix C Daily-to-Annual Factors Average daily-to-annual factors are used to calculate annual VKT. Only permanent count stations that were operational 365 days were used in the calculation. As can be seen from the table below, the factors vary depending on traffic volume, year and location within the city. Table 18. Daily-to-Annual Factor Calculation 35

36 Appendix D Average Fuel Prices in Calgary Fuel prices in Calgary fluctuated over the last five years, reaching their high in Figure 15. Fuel prices in Calgary since 2005 Calgary gas prices website accessed April 5, 2010 ( 36

37 References 1. Plan It Calgary. Where do we grow from here? Workbook, 2007 < 2. Reid Ewing, Keith Bartholomew, Steve Winkelman, Jerry Walters and Geoffrey Anderson. Urban Development and Climate Change. Journal of Urbanism, November 2008 < 3. City of Calgary. Municipal Development Plan, 2009 < 4. City of Calgary. Calgary Transportation Plan, 2009 < 5. Sustainable Transportation Indicators Subcommittee of the Transportation Research Board (ADD40 [1]). Sustainable transportation Indicators: A Recommended Research Program For Developing Sustainable Transportation Indicators and Data. November 2008 < 6. IBI Group, Transportation Association of Canada. TAC Urban Transportation Indicators Fourth Survey. Draft Final Report. November Robert Puentes, Adie Tomer. The Road Less Traveled: An Analysis of Vehicle Miles Traveled. Brookings Institution. Metropolitan Infrastructure Initiative Number 4. December 2008 < 8. U.S. Department of Transportation. Federal Highway Administration. Policy Information. Travel Monitoring. < 9. Jeffrey Kenworthy, Felix Laube. The International Source Book of Automobile Dependence in Cities, University of Colorado Press, City of Calgary. Transportation Planning. Transportation Data division. < &parentid=2&mode=2&in_hi_userid=2&cached=true> 11. City of Calgary. Transportation Planning. Forecasting division. 37

38 parentid=2&mode=2&in_hi_userid=2&cached=true 12. Guillaume Leduc. Road Traffic Data: Collection methods and Applications. EU Joint Research Centre < 38