Normal Deceleration Behavior of Passenger Vehicles at Stop Sign–Controlled Intersections Evaluated with In-Vehicle Global Positioning System Data

Abstract

Deceleration characteristics of passenger cars are often used in traffic simulation, vehicle fuel consumption and emissions models, and intersection and deceleration-lane design. Most previous studies collected spot speed data with detectors or radar guns. Because of the limitations of the data collection methods, these studies could not determine when and where drivers began to decelerate. Therefore, the studies may not provide an accurate estimation of deceleration time and distance. Furthermore, most previous studies are based on outdated and limited data, and their conclusions may not be applicable to the current vehicle fleet and drivers. The normal deceleration behavior of current passenger vehicles is evaluated at stop sign–controlled intersections on urban streets on the basis of in-vehicle Global Positioning System data. This study determined that drivers with higher approach speeds decelerated over a longer time and distance. Higher initial deceleration rates were also associated with higher approach speeds. However, the collected data in this study did not indicate a clear relationship between the average and maximum deceleration rates and approach speeds. With second-by-second deceleration profile data, the authors found that most drivers reached their maximum deceleration rates about 5 s or less than 5 s before stopping, and the maximum deceleration rate (3.4 m/s²) recommended by AASHTO was applicable to most of the study drivers. This review verified several previous deceleration models with the current observations and found that the polynomial model developed by Akcelik and Biggs provides the best fit for the data set in this study. Finally, this study developed a new deceleration model based on the approach speeds and deceleration time.