The Impact of Congestion and Dedicated Lanes on On-Demand Multimodal Transit Systems

TL;DR

This paper investigates how congestion and dedicated bus lanes influence the performance and adoption of on-demand multimodal transit systems, demonstrating that dedicated lanes significantly improve travel times and system uptake in realistic congestion scenarios.

Contribution

It introduces a bilevel optimization framework to evaluate ODMTS under congestion and assesses the impact of dedicated bus lanes through a detailed case study in Atlanta.

Findings

DBLs significantly reduce travel times.

DBLs increase system adoption.

Congestion scenarios amplify ODMTS benefits.

Abstract

Traffic congestion can have a detrimental effect on public transit systems, and understanding and mitigating these effects is of critical importance for effective public transportation. Implementing Dedicated Bus Lanes (DBLs) is a well-known intervention to achieve this goal. A DBL is a designated lane for bus transit, which avoids congestion and substantially lowers the travel time. This makes transit more attractive, encouraging more travelers to adopt public transportation. This paper studies the impact of congestion and DBLs on novel On-Demand Multimodal Transit Systems (ODMTS). ODMTS combine traditional rail and bus networks with on-demand shuttles. Previous case studies have shown that ODMTS may simultaneously improve travel time, reduce system cost, and attract new passengers. Those benefits were shown for an ideal world without traffic congestion, and this paper hypothesizes that the advantages of ODMTS can be even more pronounced in the real world. This paper explores this hypothesis by creating realistic congestion scenarios and solving bilevel optimization problems to design ODMTS under these scenarios. The impact of DBLs on ODMTS is evaluated with a comprehensive case study in the Metro Atlanta Area. The results show that DBLs can significantly improve travel times and are effective at increasing adoption of the system.