2013 Session: 222

• Observations of Daytime and Nighttime Passing Maneuvers on Two-Lane Rural Road in Spain
  Abstract: Passing is one of the most complex maneuvers on two-lane rural roads, thus it has important effects on road safety and traffic operation. It is affected by driving behavior, road geometry, traffic volume, traffic composition as well as other external factors. This research was developed to compare passing process under daytime and nighttime conditions. An experimental methodology was designed to collect video data of passing maneuvers at a two-lane rural road segment located in the surroundings of Valencia (Spain). Two methods were used: firstly, external observations with six video cameras of four passing zones; secondly, an instrumented vehicle equipped with video cameras and laser rangefinders, which was drivenove slightly below the operating speed along a longer road segment of the same road in order to be passed by other vehiclesdrivers.A total of 291 maneuvers were observed; up to 20% of them during night. A macroscopic analysis shows that approximately 17% of passes are under nighttime conditions, although passing frequency and passing demand decrease during night. Besides, individual behavior of drivers which pass is different at nighttime compared with daytime. Maneuvers limited by the presence of an opposing vehicle are performed faster at night, even if accepted gaps are longer. In this case, a more difficult perception of distances to opposing vehicles and of their speeds explains the differences. On the other hand, maneuvers limited by sight distance (without a visible opposing vehicle) are slower during night. This matches a traditional hypothesis, which assumed that passing at night is safer since headlights from opposing vehicles anticipate their position before being seen.
  Authors: Llorca, Carlos; Moreno, Ana Tsui; Garcia, Alfredo; Perez-Zuriaga, Ana Maria
  Authors: Llorca, Carlos; Moreno, Ana Tsui; Garcia, Alfredo; Perez-Zuriaga, Ana Maria
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-0953
• Safety Issues in Design of Dual Right-Turn Lanes
  Abstract: This study is to investigate safety issues in the design of dual right-turn lanes. Historical crash records at 19 dual right-turn lanes were collected and analyzed to identify the contributing factors to different types of right-turn related crashes. In addition, the historical crash records for the dual right-turn lanes were compared to those for single right-turn lanes with similar traffic conditions. Based on the results of this study, several issues in the design of dual right-turn lanes were identified and recommendations for improvements were provided. It was found that dual right-turn lanes that are well designed do not cause more crashes than single right-turn lanes. This study can help traffic engineers to better design and implement dual right-turn lanes
  Authors: Qi, Yi; Wang, Yubian; Chen, Xiaoming
  Authors: Qi, Yi; Wang, Yubian; Chen, Xiaoming
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-2071
• Safety Impacts of Increasing Lengths of Left-Turn Lanes
  Abstract: Left-turn lanes can improve the safety and operation of intersections by providing space for deceleration and storage of turning vehicles. The length of the lane is critical in the design of left-turn lanes. Insufficient length may result in left-turn lane overflow which seriously impacts the safety of the intersection. The objective of this research is to determine the safety impacts of increasing storage lengths of the left-turn lanes. To achieve the objective of this research, field study was conducted at the intersections with different geometric, signal timing, and traffic flow conditions. Two approaches were employed to determine the safety benefits of increased storage lengths of left-turn lanes: 1) accident data analysis, and 2) simulation-based safety analysis. The research concludes that extending the length of left-turn lane to eliminate the left-turn lane overflow problem can significantly reduce the risk of rear-end accidents.
  Authors: Qi, Yi; Azimi, Mehdi; Yu, Lei
  Authors: Qi, Yi; Azimi, Mehdi; Yu, Lei
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-2097
• Roadway and Infrastructure Design and Its Relation to Pedestrian and Bicyclist Safety: Basic Principles, Applications, and Benefits
  Abstract: Road deaths are forecast to double by 2020, with the burden falling most heavily on low- and middle-income countries and, within those countries, on the most vulnerable and poorest road users. Half of the 1.2 million people killed and 50 million injured in road crashes each year are pedestrians, motorcyclists, bicyclists, and users of unsafe public transport; and more than 90 percent are from low- and middle-income countries. Because these are the areas where rapid motorization is taking place, the issue of safety in increasingly multi-modal environments is now of critical importance, particularly for pedestrians and bicyclists, since as vulnerable road users (VRU), they comprise a large proportion of injuries and deaths, and similar strategies for prevention of injuries and fatalities for these two groups are available. Although a great deal of additional research is needed to determine the costs and benefits of various proposed solutions, some basic principles can be identified to guide roadway and infrastructure design for improved pedestrian and bicyclist safety. The three broad but separate strategies for reducing the probability of an injury or fatality are: (i) reducing exposure, (ii) reducing the probability of a collision given exposure, and (iii) reducing the probability of injury given a collision. The purpose of this paper is to describe and illustrate these principles, discuss issues related to each one, and discuss the benefits—indeed, imperativeness—of the application of these principles by planners and traffic engineers.
  Authors: Ragland, David R.; Grembek, Offer; Orrick, Phyllis; Felschundneff, Grace
  Authors: Ragland, David R.; Grembek, Offer; Orrick, Phyllis; Felschundneff, Grace
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-4820
• Safety Issues in Design of Dual Right-Turn Lanes
  Authors: Qi, Yi
  Authors: Qi, Yi
  Year: 2013
  Document Type: Presentation
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-2071
• Safety Impacts of Increasing Lengths of Left-Turn Lanes
  Authors: Azimi, Mehdi
  Authors: Azimi, Mehdi
  Year: 2013
  Document Type: Presentation
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-2097
• Observations of Daytime and Nighttime Passing Maneuvers on Two-Lane Rural Road in Spain
  Authors: Llorca, Carlos
  Authors: Llorca, Carlos
  Year: 2013
  Document Type: Presentation
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-0953
• Roadway and Infrastructure Design and Its Relation to Pedestrian and Bicyclist Safety: Basic Principles, Applications, and Benefits
  Authors: Ragland, David
  Authors: Ragland, David
  Year: 2013
  Document Type: Presentation
  Subject: Design; Safety and Human Factors
  Session: 222
  Paper Number: 13-4820