Evaluating Safety of Type-A Weaving Sections Using Geometric and Traffic Operational Factors

Abstract

The efficiency and safety of type-A freeway weaving sections in urban areas are constrained by recurrent bottlenecks. Limited space in freeway weaving sections cause traffic congestion and crashes during peak-hours. Various factors, including length of weaving section, continuity of lanes, and number of lanes will have significant effects on the level of service and safety performance of the weaving sections. Eight years (2010-2017) of crash data in the type-A weaving sections was used in this analysis. The objective of this study aims to evaluate geometric design factors and operational factors on total crashes and each of the four crash types: rear-end, sideswipe, angle, and single-vehicle in type-A weaving sections using traditional negative binomial approach and develop crash modification factors (CMFs) to improve safety in the type-A weaving section. The results revealed that on-ramp traffic per hour, off-ramp traffic per hour, non-weaving traffic per hour, weaving ratio, length of the weaving section, direction of the freeway, width of inside shoulder, and width of outside shoulder were influencing crashes in type-A weaving sections. Furthermore, the estimated crash modification factors (CMFs) result revealed that total crashes gradually decrease as inside shoulder width increases. This implies that widening inside shoulder width have positive effects on weaving section safety. In addition, ramp metering, and advisory warning signs could improve safety in type-A weaving sections.

Analysis of Traffic Characteristics and Distance Optimization Design between Entrances and Exits of Urban Construction Projects and Adjacent Planar Intersections

“…They believed that increasing the proportion of intelligent connected vehicles and queue size can increase the maximum traffic volume, and an appropriate queue size can reduce average energy consumption. In addition to queuing sections, for intertwined sections with significant vehicle conflicts, the length, lane continuity and the number of lanes can also have a significant impact on the level of service, safety performance and distance between entrances and intersections [22,23]. In intertwined sections, vehicles on major roads were also more likely to change lanes earlier than vehicles on minor roads [24].…”