Simple Approach to Estimating Changes in Toll Plaza Delays

Abstract

Toll plazas are important components of the road infrastructure, especially on urban highways. They can have adverse capacity and safety impacts on traffic. However, the plazas serve an important purpose, namely, revenue generation for highway agencies. Various traffic management and electronic toll collection strategies, including regular and high-speed E-ZPass and time-of-day pricing, are also implemented as part of toll plaza operations to change traffic supply and demand characteristics and improve networkwide level of service. In recent years, because of the increasing need to better assess the impact of toll plazas combined with these various traffic management strategies, customized or off-the-shelf microsimulation and macrosimulation models of toll plazas have been developed. This study reviews the literature on both approaches. Then a customized microscopic toll plaza model developed as an integrated part of PARAMICS microsimulation is compared with a relatively simple macroscopic model. This kind of macroscopic model, which can estimate toll plaza delays, is needed because it is extremely difficult and expensive to calibrate and implement microsimulation models when projects have severe budget and time constraints. Several New Jersey Turnpike toll plazas that were well validated and calibrated are used in the comparison. A sensitivity analysis is conducted with various other toll plazas to ensure the validity of the macroscopic model, especially for cases in which demand is reduced because of a real-time traffic management strategy. Results indicate that the macroscopic method is comparable (within average error 2.6% to 6.4%) with the PARAMICS model when sufficient care is taken in selecting macroscopic and microscopic model parameters consistently.