Enhancing Motorway Exit Efficiency: Determining the Ideal Number of Toll Booths

Abstract

This study presents a model for determining the optimal number of toll booths at barrier-operated motorway exit toll booths in Istanbul, considering mixed traffic conditions and payment methods. In the past decade, Istanbul has experienced rapid growth in its road network due to public-private partnership (PPP) projects. However, despite relatively modest demand, long queues are frequently observed at the exit toll booths of newly constructed PPP motorways, which utilize barrier- controlled toll collection systems. These toll booths offer both electronic toll collection (ETC) and manual toll collection (MTC) options, with MTC users required to come to a complete stop for transactions, while ETC users experience reduced speeds. The presence of mixed payment methods leads to significant interactions between vehicles, resulting in longer service times and limited toll booth capacity. To evaluate the system, service times were measured considering four vehicle classes, payment methods of both the leading and serving vehicles, and whether the serving vehicle needed to wait for money exchange. The findings reveal that based on the current vehicle composition and considering only the utilization of the ETC system, 1.77 toll booths would be required to serve a demand of 1,800 veh/h/lane.