Integrated demand estimation and traffic operations analysis approach for managed lane facilities

Abstract

To improve congested freeways without adding lanes, many agencies are studying managed lanes, including high-occupancy toll (HOT) lanes or congestion-priced lanes. Although some elements of managed lanes have been researched in great detail, there has been little discussion related to demand estimation and operations simulation within managed lane facilities. This paper presents an integrated methodology to estimating demand and traffic operations for managed lanes, using State Route 52 (SR-52) in San Diego as an example. SR-52 is a congested freeway corridor, with highly directional traffic, so it is well-suited for managed lanes improvements. To analyze potential strategies, it was important to estimate future demand from the regional travel demand model, and also conduct an operational assessment using a traffic simulation model. To ensure that the traffic patterns in the two models were compatible, a customized static origin-destination (O-D) matrix was developed for the analysis. An iterative process was used to balance the demand between the elements of the facility, especially when traffic moved between the managed lanes and general purpose lanes. The final O-D matrix provided an accurate estimate of future traffic, allowing for the analysis of operational strategies on the managed lanes. The methodology presented in the paper can serve as a guide for analysts and researchers conducting similar studies.