Braking behavior of major approach turning vehicles at rural two-way stop controlled intersections: A naturalistic driving study

Abstract

Objective: Using naturalistic driving data, this study analyzed the driving behavior of major approach right and left turning vehicles to minor approach at rural two-way stop controlled intersections by detecting the location where drivers reacted to the upcoming intersection to complete a turning maneuver.

Methods: The study used 449 time series traces from 29 two-way stop controlled intersections across five states for the analysis. All 449 traces were associated to free flow condition with driving not obstructed by the vehicle ahead. Each time series trace was analyzed to check the point drivers first reacted to the intersection for the turning maneuver and this point was called the reaction point. Braking Behavior of Major Approach Turning Vehicles at Rural Two-Way Stop Controlled Intersections: A Naturalistic Driving Study

Results: The results from this study showed that right turning vehicles began reacting, in general, sooner than left turning vehicles. More than 75% of drivers showed a reaction within 300 meters upstream of intersection for both types of turning maneuver. The study found driving speed at the reaction point significantly affecting the initial point of reaction. Drivers who were traveling faster than the posted speed limit were associated with a reaction point farther upstream than vehicles traveling at the speed limit. On-pavement marking upstream of the intersection was found to be associated with longer reaction distance, while posted intersection ahead warning signs showed a reverse effect. The result provides information on braking zone of turning vehicles at intersections which has implication on the placement of different countermeasures upstream at the major approach.

Conclusions: By detecting reaction distance of all 449 time series trace, the study provides an influence area of the intersection for the turning vehicles.

Keywords:

• Reaction point
• turning vehicles
• braking zone
• speed limit
• upstream of intersection

Acknowledgement

The team would like to thank Federal Highway Administration (FHWA) and the Iowa Department of Transportation for funding this research, the Virginia Tech Transportation Institute for their assistance in obtaining the SHRP2 data, and the Center for Transportation Research and Education (CTRE) at Iowa State University for providing the RID data.