Left-Turn Gap Acceptance Behavior of Elderly Drivers at Unsignalized Intersections

Abstract

This article describes an investigation of possible differences in elderly drivers’ gap acceptance behavior from other drivers when making left turns across oncoming traffic at unsignalized intersections. Elderly and other drivers were observed turning left at two unsignalized intersections with different speed limits of major roads. Statistical analyses were used to identify whether older drivers choose different gaps for left turns. Results indicated that drivers older than age 70 were different from drivers younger than age 35 and drivers age 55 to 69 in gap selection and female drivers different from male drivers. Finally, traffic simulations were run in VISSIM to determine how age differences in gap acceptance impact traffic operations. Results showed significant differences in the delay time, the number of stops per vehicle, and the total delay time of the network for drivers older than age 70 and other drivers under the same traffic conditions.

Keywords:

• elderly driver
• gap acceptance
• left turn
• correlated binary model

Funding

The research described in this article was supported by the New England University Transportation Center, a program of the United States Department of Transportation and the Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University.