Development of Toll Equivalency Factors for FASTag Lanes Under Mixed Traffic Conditions

The traffic conditions in India consist of a high degree of heterogeneity in vehicle categories plying on the highways without any lane-following behavior. A similar behavior is observed at the toll plazas where a dedicated lane assigned to a vehicle class is encroached by the vehicles of other categories, causing a mixed nature of the traffic in the same lane. In the present study, service headway is taken as the measure of effectiveness for studying the effect of mixed traffic conditions on traffic operations at electronic toll collection system (ETC) lanes, which are called FASTag lanes in India. Service headway is composed of processing time and the clearance time of the vehicle. Videographic data were collected at three different toll plazas located on National Highways in India to capture the variability in traffic and human behavior. The results showed that the service headway for a vehicle varies between 1.56 s and 34.40 s. The service headway-based toll equivalency factors (HTEF) are developed for converting the mixed traffic flow into a homogeneous equivalent for FASTag lanes. The results showed that the HTEF varies from 1.01 to 2.61. The results are validated spatially with data taken from a different site, and no significant difference was found between both the converted and equivalent data. Field engineers can use the developed HTEFs to estimate the traffic flow in equivalent terms based on the traffic composition. Further, the present study results can also be used to study the capacity and level of service (LOS) of FASTag lanes.