Mobility for all

Self-driving car technology will change not just how we travel, but who travels. The mobility of non-driving populations, for example, could increase up to 14%, according to Corey Harper, a Civil and Environmental Engineering Ph.D. student and lead author of the award-winning paper “Estimating potential increases in travel with autonomous vehicles for the non-driving, elderly, and people with travel-restrictive medical conditions.”

In December 2016, this article was selected for an Elsevier Atlas Award. Each month, Elsevier, a publisher of over 1,800 academic journals, recognizes research that could significantly impact people’s lives around the world. The article, which appeared in Transportation Research Part C: Emerging Technologies, was co-authored by CEE professors Chris Hendrickson and Constantine Samaras and EPP Ph.D. student Sonia Mangones.

The idea for the research came about after Harper and his collaborators reviewed self-driving car literature and realized there wasn’t much published on how this technology would affect non-driving populations or those who have trouble traveling independently.

“This is technology that promises mobility, but if so, how will it actually increase the travel of populations that could benefit from vehicle automation? If we don’t explore these things, our transportation systems will have trouble providing efficient service to these people,” explains Harper.

The researchers looked at data from the 2009 National Household Transportation Survey to understand travel characteristics of three groups: non-drivers, elderly drivers, and drivers with a self-reported medical condition.

If we don’t explore these things, our transportation systems will have trouble providing efficient service to these people.

Corey Harper, Civil and Environmental Engineering Ph.D. student, Carnegie Mellon University

To estimate potential increases in vehicle miles traveled (VMT), they assumed that self-driving cars would allow elderly drivers, who may want to travel more but are limited by age, to increase their VMT to match that of a young adult.

Based on their analysis, the team found that when they combined the three groups, VMT could increase by as much as 14% or 295 billion miles, with elderly females (who stop driving substantially earlier than their male counterparts) and non-drivers making up most of the increase.

The study suggests that self-driving technology could significantly help underserved populations that currently rely on relatives, public transportation, or other assistance to travel. “With self-driving cars, things like age and disability will not be as much of a prohibitive factor when it comes to owning and operating a vehicle,” says Harper.

Harper, who spent last summer working alongside some of the nation’s top safety researchers at the National Highway Traffic Safety Administration (NHTSA) in Washington, DC, has deep interest in improving the current transportation system for everyone.

“I think the next step is to look at the travel needs of these populations with a finer scope if we want to address larger mobility issues,” says Harper. “This paper deals with the demand side of self-driving cars, and I think what’s next for us is to think about the supply side of this demand—What technologies do we need to put in cars, and how can we encourage these underserved populations to travel?”