Principles of Road and Traffic Engineering Designs for Mixed Traffic Flow with a Numerous Motorcycles

Transcription

1 Principles of Road and Traffic Engineering Designs for Mixed Traffic Flow with a Numerous Motorcycles Dr. Ming-Heng Wang Assistant Professor, Department of Transportation Technology and Management, Kainan University, Taiwan. Dr. Wucheng Chen Dean, Office of Academic Affairs Kainan University, Taiwan. Dr. Cheng-Chen Kou Assistant Professor, Department of Transportation Technology and Management, Kainan University, Taiwan. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

2 Presentation Outlines Introduction Motorcycle Management Strategies Motorcycle Helmet Use Law Motorcycle Two-stage Left Turn at Intersections Motorcycle Waiting/Stop Zone Motorcycle Banned Lane Motorcycle Exclusive/Priority Lanes Motorcycle Accident Analysis Principles of Road and Traffic Engineering Designs Conclusions and Recommendations 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

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4 Introduction(1/2) In 2012, there were 15 million registered motorcycles in Taiwan, representing approximately 68 percent of all 22.3 million registered automobiles. In 2011, there were 235,775 fatal or injured traffic accidents (FITAs) and 88 percent of them were motorcycle-involved accidents. This fact indicates that motorcycle safety should be a highly important issue for transportation management in Taiwan. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

5 Introduction(2/2) Most of the motorcycle management policies in Taiwan merely focused on separating or isolating the motorcycles from mixed traffic to decrease usage and restrict the rights of motorcyclists. Road designs seldom took into account the high number of motorcycles as well as the motorcyclists points of view. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

6 Major Tasks of This Study Existing Taiwanese principles of road designs and motorcycle-specific traffic control devices or strategies were introduced. Motorcycle crashes in 2011 were analyzed to identify the major contributors of crashes due to road design issues. The principles for establishing guidelines for road designs and traffic control devices were proposed. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

7 Motorcycle Management Strategies Motorcycle Helmet Use Law Motorcycle Two-stage Left Turn at Intersections Motorcycle Waiting/Stop Zones Motorcycle Banned Lane Motorcycle Exclusive/Priority Lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

8 Motorcycle Helmet Use Law(1/2) A motorcycle helmet use law was approved and implemented in Taiwan on June 1, Implementation of the motorcycle helmet use law was credited with a 51 percent reduction in motor vehicle-related deaths in Taiwan over 15 years (from 1996 to 2011), despite a 63 percent increase in the number of motorcycles. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

9 Motorcycle Helmet Use Law(2/2) However, the number of traffic accidents increased as the number of registered motorcycle increased indicating that the motorcycle helmet use law passively prevented deaths from traffic crashes but didn t reduce the occurrence of traffic accidents. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

10 Motorcycle Two-stage Left Turn at Intersections(1/4) In Taiwan, the implementation of motorcycle two-stage left turn (MTLT) regulation began as far back as Left-turning motorcycles need to proceed straight across an intersection to the painted motorcycle box (two-stage left-turn box) and wait there for the other traffic signal to turn green. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

11 Motorcycle Two-stage Left Turn at Intersections(2/4) Left-turning waiting box 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

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14 Motorcycle Two-stage Left Turn at Intersections(3/4) The location of the left-turning waiting box may create conflicts between left turning and straight moving motorcycles. The crosswalk and the stop line need to be moved back to create space for the left-turning waiting box increasing the crossing length and also reducing the sight distance of the intersection. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

15 Motorcycle Two-stage Left Turn at Intersections(4/4) At T-intersections, the implementation of a two-stage left turning motorcycle waiting zone becomes difficult. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

16 Motorcycle Waiting/Stop Zones(1/3) Since 2000, motorcycle waiting zones have officially been installed beyond the stop line at signalized intersections where the speed limits are less than 60 KPH in Taiwan. Motorcycles stop/waiting box 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

17 Motorcycle Waiting/Stop Zones(2/3) The major purpose of Motorcycle Waiting/Stop Zones is to increase the vehicle discharging rate at signalized intersections. Based on this design, motorcyclists are encouraged to overtake slow or stopped vehicles by traveling between lanes, called lane splitting, to stop and wait in Motorcycle Waiting/Stop Zones during the red light period. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

18 Motorcycle Waiting/Stop Zones(3/3) One of the major issues for the Motorcycle Waiting/Stop Zones is the dilemma zone would be changed and the clearance time for the signal timing should be modified as the stop line of the vehicles moved backward from the intersections. The other issue is that there is no official regulation which allows motorcycles to travel between two driving lanes, called lane splitting. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

19 Motorcycle Banned Lane(1/2) The purpose of this Motorcycle Banned Lane design is to prevent motorcycles from traveling in the major traffic stream and reduce the conflicts between motorcycles and other motor vehicles. A consequence of this design is a reduction in the lane space that motorcyclists are allowed to travel. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

20 Motorcycle Banned Lane(2/2) Although the mixed traffic situation can be omitted at these Motorcycle Banned Lanes, the mixed traffic situation becomes worse because all motorcycles are limited to the remaining lanes or road sides. The speed differentials within the mixed traffic on the road-side lane become larger as various types of road users, such as cars, motorcycles, bicycles, or even pedestrians, are combined on road side lanes. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

21 Motorcycle Exclusive/Priority Lanes(1/2) For segregating motorcycle traffic from the other fast vehicle traffic, there are separated Motorcycles Exclusive/Priority Lanes on some major roads. On most urban streets, Motorcycles Exclusive/Priority Lanes are likely to be occupied by parked vehicles forcing motorcyclists to travel on the nearby Motorcycle Banned Lanes. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

22 Motorcycle Exclusive/Priority Lanes(2/2) 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

23 Motorcycle Accident Analysis In 2011, the total number of motorcyclistinvolved accidents (MIAs) was 208,498, which is about 88 percent of the total traffic accidents that same year in Taiwan. The 2011 Motorcyclist-involved accidents resulted in 1,673 deaths and 263,356 injures to motorcyclists. Among those deaths and injuries, 113 deaths and 29,103 injuries were motorcycle passengers. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

24 Motorcycle Accident Analysis The 2011 data show that about 33 percent of Motorcyclist-involved accidents were motorcycle-only accidents, 7 percent involved pedestrians and bikers, and 60 percent were with other motor vehicles. More than 60 percent of Motorcyclist-involved accidents occurred at intersections. When multiple motorcycles were involved in accidents, 67 percent occurred at intersections. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

25 Motorcycle Accident Analysis - Intersection For those accidents that occurred at intersections, more than half (52 percent) of the MIAs occurred at unsignalized intersections. The major cause of the MIAs at unsignalized intersections was fail to yield (47 percent), followed by failed to look properly (10 percent). 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

26 Motorcycle Accident Analysis Crush Causes at Unsignalized Intersection 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

27 Typical unsignalized intersections in Taiwan (No proper signs or markings) 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

28 Motorcycle Accident Analysis Crush Causes at Signalized Intersection At signalized intersections, the main crash cause of MIAs was against signal indications (21 percent), followed by failed to yield (20 percent) and failed to look properly (10 percent). 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

29 Motorcycle Accident Analysis Crush Causes at Signalized Intersection 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

30 Motorcycle Accident Analysis Road Segment For the locations where the MIAs occurred at road segments, more than 82 percent of MIAs occurred at either general lanes (57 percent) or road side lanes (25 percent). On road side lanes, the major crash cause of MIAs was failed to look properly (23 percent). A high portion (9 percent) of crashes between motorcycles and other motor vehicles was due to changing lanes improperly. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

31 Motorcycle Accident Analysis Crush Causes at Road Side Lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

32 Motorcycle Accident Analysis Crush Causes at General Lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

33 Motorcycle Accident Analysis Crush Types on Road Segments Angle crashes and fender-bender crashes are the major crush types on road segments. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

34 Chaos of Motorcycles Traveling on the Same Lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

35 Principles of Road and Traffic Engineering Designs The basic principle of road design and traffic control devices should treat motorcycles as regular, although weaker, motor vehicles instead of labeling motorcycles as slow vehicles. The lane alignment and size of motorcycle waiting boxes should take into account motorcycle volumes, motorcyclists characteristics and road-side land use types. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

36 Principles of Road and Traffic Engineering Designs Unsignalized Intersections Clear signs or markings, such as a stop sign, at every unsignalized intersection approach is needed to assign the prior sequences for the approaching vehicles. Drivers therefore can follow the rules of the obvious signs or markings for passing the unsignalized intersections and need not rely on self-judgment about the priority sequence from a set of complicated regulations. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

37 Principles of Traffic Control Design at Signalized Intersections for Motorcycles Motorcycle signal sets or indications At a four-way intersection, the basic signal sets include a near right set and a far left set. Due to the size and location of motorcycles, the signal indications tend to be blocked by other vehicles using the main driving lanes. Supplemental sets of traffic signals or indications are needed, such as a vertical signal set along the road side or a supplemental little signal set commonly used in a French intersection. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

38 Standardized Signal Location and Indications at Signalized Intersections in Taiwan 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

39 Examples of Supplemental Sets of Traffic Signals Along the Road Sides 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

40 Principles of Traffic Control Design at Signalized Intersections for Motorcycles Signal indications by lanes The standardized signal and indication settings in Taiwan usually do not consider the types of vehicles or lanes. Separated signal indications by lanes are recommended, especially for the approaches with Motorcycle Priority/Exclusive Lanes, or other physically separated lanes. For these separated lanes, separated signal timings may also be an option based on motorcycle volume and demand. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

41 Principles of Traffic Control Design on Road Segments for Motorcycles Principle of installing Motorcycle Priority/Exclusive Lanes Various speed limits by lanes Lane Splitting Supplemental motorcycle lane markings on general lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

42 Principle of Installing Motorcycle Priority/Exclusive Lanes It is not recommended on urban streets where a high number of parking activities occur. In rural areas, exclusive motorcycles lanes are recommend on major roads. Motorcycles and slow vehicles should be treated separately. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

43 Principle of Various Speed Limits by Lanes A clear statement or regulation to regulate the speed limits by lanes is recommended. Vehicles driving on the Shared Vehicle Lanes should drive at a slow speed regardless of the type of the vehicle driven. Vehicles driving on the Fast Vehicle Lanes should drive at a high speed, whether there are motorcycles or cars on the lane. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

44 Principle of Lane Splittings A clarified regulation of lane splitting exclusively for motorcycles is needed to support the installation of motorcycle waiting boxes beyond the stop line. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

45 Principle of Supplemental Motorcycle Lane Markings on General Lanes Regular line for general Supplemental line for motorcycle lanes 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

46 Conclusions (1/2) Motorcycles are the most common mode of transportation but also create the major safety issue in Taiwan. A long-term goal of the Taiwanese government is to reduce its usage and dependency on motorcycles. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

47 Conclusions (2/2) Restricting the space permitted for motorcycle use would not decrease the usage of motorcycles but instead deteriorate their traveling environment. Providing motorcyclists with an appropriate and suitable traveling environment would be the best solution for improving motorcycle safety. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

48 Recommendations (1/2) At unsignalized intersections, a physical and visible traffic sign or marking should be implemented to clearly assign the passing priority for approaching vehicles. At signalized intersections, supplemental sets of signal indications for motorcycles are needed to provide a clear signal indication for vehicles traveling on the road s side lanes. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

49 Recommendations (2/2) On road segments, the implementation of motorcycle exclusive and priority lanes should take into account the land use of the road side. Various speed limits by lanes and supplemental markings for motorcycles to stay on tracks or lanes. 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,

50 Thank you! 26 th ICTPA Annual Conference, Tampa, Florida, USA, May 24-26,