Real-Time Ridesharing Texas Experiments with Toll Roads and Carpools

The New Science of Carpooling

The primary goal for this study was to determine if the number of occupants in a vehicle can be verified through a real-time ridesharing service, which has been confirmed. This may allow transportation agencies to offer incentives like toll discounts to verified carpools in the future, without requiring a problematic physical observation of vehicle occupancy.

Next, the study is evaluating whether toll road discounts received through real-time ridesharing are an effective method to encourage carpooling. As people sign on to the program, TTI is surveying them on their travel behaviour, then following up after users have been in the program for at least a month. Their responses, in addition to the data received through Carma and toll transactions, are providing evidence that this may be a feasible method from both the individual’s perspective to increase carpooling; and the operator’s perspective, since occupancy verification is possible through the ridesharing technology.

Since the project includes various recruitment techniques observed over almost a year, this pilot will yield new information about what strategies to encourage carpooling are most effective. Since transit service is offered in limited areas, real-time ridesharing may offer a prospect for mobility for people who cannot afford vehicles, or choose not to drive.

As of this writing, early responses are indicating the participants are taking carpool trips at a higher rate than the larger population, however the results will not be complete until the pilot is concluded and analysed in Spring 2015. These new software tools and transportation agency coordination are providing new options that will change passenger transportation, but true ridesharing services have not been evaluated in many different countries and contexts.

Is this something that will work in other places?

This specific combination of smartphone technology and tolling discounts will be restricted to locations with adequate technology adoption rates and roadway toll information that allows processing of discounted tolls through confirmed carpool trips. Results can be expected to vary in different populations as smartphones, Internet and vehicle access rates continue to change. Evaluation of how these rates affect real-time ridesharing in similar areas will help transportation agencies plan for the future.

Looking ahead, there are a suite of options that have not been explored. For instance, are there communication networks beyond smartphones that offer promise to coordinate carpooling? Are incentives other than toll discounts significant enough to encourage sharing rides? How will upcoming in-vehicle technologies provide information to help drivers choose effective routes, and even logical carpool riders? Only time, and our carpoolers, will tell.

Greg Griffin

Associate Transportation Researcher

Texas A&M Transportation Institute