The impact of a toll reduction for truck traffic using SH 130

Abstract

This research investigated the impact of a toll reduction for trucks on SH 130 and the resulting changes in the number of trucks using the road. SH 130 is a tolled bypass facility, running parallel to Interstate 35 (I-35), around the Austin area. This toll road was constructed, in part, to divert traffic from I-35 which runs through Austin. However, the toll road was only partially successful in attracting truck traffic since many truck drivers felt the toll was high compared to the travel time saved. Hence, beginning on March 1, 2011, Texas Department of Transportation reduced the toll rate by 25% for 5-axle vehicles and 40% for 6 plus-axle vehicles. A toll reduction is relatively rare and there are very few studies on how this may impact truck travel.A time series analysis of the toll transaction data, along with the local price of diesel fuel, unemployment rate, GDP, and income levels, resulted in a toll-price elasticity of −0.43 for 5-axle vehicles (the vast majority of 5-plus axle vehicles). Thus, the drop in toll was successful in attracting additional trucks – but also resulted in decreased revenues from tolls. The majority (94%) of 5-axle vehicles paid using electronic toll collection (ETC), and the remainder paid manually (MLT). The toll-price elasticity for 5-axle vehicles paying by ETC was −0.39 while it was −1.49 for those paying by MLT. Thus MLT vehicles were much more price sensitive to the toll reduction, possibly indicating new users of the road who had not signed up for ETC before the toll reduction.