At unsignalized intersections on rural highways with high speed limits, drivers' views on the minor road are likely being blocked by the vehicles in the right-turn lane of the major road. Therefore, potential conflicts due to intermittent sight distance obstructions may occur between vehicles in minor roads and those in major roads. To reduce the potential conflicts, a right-turn lane is offset from the through lanes at these intersections. Thus, a clear view of the through movements on the major road could be provided to the drivers on the minor road. Field data were collected at the four study locations in Illinois, and historical crash data were collected to understand the possible safety problems at the sites with conventional right-turn lanes. A new probabilistic model was developed to predict the potential traffic conflict rates. Traffic simulation software TSIS/CORSIM was used to verify the probabilistic model and determine the frequency of the potential conflicts for different traffic-flow conditions. This methodology and its results provide the traffic agencies and policy-makers with a step forward to design guidelines which determine when to install the offset right-turn lane based on the potential conflict occurrence to proactively improve the safety at unsignalized intersections.
Prediction of intermittent sight distance obstruction at unsignalized intersections with conventional right-turn lanes
Journal of Transportation Safety & Security ; 9 , 1 ; 64-81
2017-01-02
18 pages
Article (Journal)
Electronic Resource
English
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