IMPACT OF TRAFFIC FLOW CONDITIONS ON VEHICLE SPEEDS IN ETC LANES - A CASE STUDY OF A TOLL PLAZA IN SERBIA

Abstract

Barrier-based ETC (Electronic Toll Collection) systems enable automated toll payment, eliminating the need for stopping, thereby allowing higher travel speeds and increasing lane capacity compared to conventional manual toll collection systems. In Serbia, a significant increase in the number of ETC tag users has been recorded in recent years, highlighting the importance of improving and efficiently implementing electronic toll collection systems. This paper analyzes vehicle speeds in barrier-based ETC lanes as a function of vehicle category and traffic flow conditions. An empirical study was conducted at the mainline toll plaza Stara Pazova on the A1 motorway, where vehicle speeds were measured within the influence area of ETC lanes. The objective of the study is to examine the existence of statistically significant differences in mean speeds between vehicle categories and different traffic flow conditions, as well as to evaluate the credibility of the posted speed limit within the ETC lane influence zone. The results indicate that traffic flow conditions have a significant impact on vehicle speeds when passing through ETC lanes, while differences between vehicle categories decrease with increasing levels of saturation. The findings contribute to a better understanding of the operational characteristics of barrier-based ETC lanes and may serve as a basis for improving toll plaza management, design parameters, and capacity estimation models in toll station areas.