ICT/IDOT Study Finds Environmental and Economic Benefits in Bus-Only Shoulder Service

To help ensure Illinois residents and other stakeholders benefit from its research projects, the Illinois Department of Transportation (IDOT) emphasizes research implementation.

One implemented project of note is based on a study the Illinois Center for Transportation (ICT) conducted with IDOT. That study, “Bus Riding on Shoulders” (R27-005), investigated the feasibility of “bus on shoulder” (BOS) service in the Chicago metro area. With BOS service, public transit buses may ride on designated highway shoulders when vehicles in the general traffic lanes are moving less than 35 mph. This practice gives public transit riders a faster and more reliable traveling experience when the highway’s general traffic lanes are congested.

To address stakeholder concerns about the feasibility of BOS service, the ICT research team reviewed the literature on safety and operational aspects of bus on shoulder use and the ways in which shoulder use have been incorporated to manage congestion in several regions. The researchers found that highway shoulders have served various purposes in many regions over time with proper precautions and appropriate authorization.

Because safety is a primary concern, the research team also looked at crash incidence, conflicts with on- and off-ramps, “copycat” cars using the shoulders, impacts on motorists in adjacent lanes, debris on shoulders, speed differentials, and resolution of financial and legal factors surrounding BOS operations.

Paul Metaxatos, one of the project’s principal investigators, says, “We concluded that BOS operations are feasible for northeastern Illinois, but success would depend on selection of the right highway segments, bus driver education and training, and awareness among motorists.” Metaxatos is the associate director for research programs and a research associate professor at the University of Illinois at Chicago’s Urban Transportation Center.

BOS operations started on a segment of I-55 in 2011 after legislation passed allowing for a trial demonstration. The Illinois legislature, IDOT, and Pace deemed this trial demonstration a success. The Illinois legislature made the program permanent. Expanded service on I-55 is planned, along with service on I-94 (Edens Expressway), and the Illinois Tollway.

The implementation cost to date is $9.5 million dollars—primarily associated with roadway improvements such as pavement and signage. In addition, $90,600 was provided as funding for the initial research project. The benefits, though, are far-reaching: increased on-time transit bus service, reduced commuter time, increased bus ridership, parking savings, and environmental benefits arising from fewer vehicles and less traffic congestion. The estimated value of those benefits is $22.9 million dollars over the next 16 years.

Chuck Abraham, Manager of Program Support (Planning) for IDOT’s Department of Public and Intermodal Transportation, served as chair of the Technical Review Panel that supervised this research. He says, “This project shows how innovation and cooperation among agencies can result in relatively inexpensive improvements with large gains for Illinois’ transit riders.”

A recent press release on the program is available on the State of Illinois website.