While self-driving cars are expected to increase vehicle safety, mobility, and convenience, transportation researchers are concerned that that too many people may be using them.

Researchers predict the number of miles driven will skyrocket, and could add to traffic congestion. Self-driving cars will likely be used for more trips including chauffeuring children to school and afterschool activities; disabled and elderly people having new mobility options; and people choosing to stay home more and send their cars out for several chores like delivering groceries they’d ordered online.

KPMG predicts “mobility-on-demand” services, similar to ridesharing and delivery services like Uber, will see strong demand. Based on focus groups in Atlanta, Denver and Chicago, KPMG predicts these autonomous vehicle services will result in double-digit increases in travel by people in two age groups: those over 65, and those 16 to 24.

Vehicles traveled a record 3.1 trillion miles in the U.S. last year. Increased trips in autonomous cars by those two age groups would boost miles traveled by an additional two trillion miles annually by 2050, according to KPMG calculations. If self-driving cars without passengers start running errands, the increase could be double that, according to KPMG.

“It will be indispensable to your life,” said Gary Silberg, an auto industry expert at KPMG. “It will be all sorts of things we can’t even think of today.”

Autonomous vehicles capable of driving under limited conditions are expected to be on roads within five-to-10 years. Fully autonomous vehicles may take 10 to 20 years.

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While driverless cars are expected to make roads safer, there are incentives built in for using cars more often. Taking human error out of driving will dramatically reduce crashes, with human error responsible for 90 percent of traffic accidents. For Don MacKenzie, a University of Washington transportation researcher, benefits gained may be undercut when people find they can use their driving time productively on other tasks.

A study by MacKenzie and other researchers published in the journal Transportation Research: Part A estimates that self-driving vehicles will be able to cut the cost of travel by as much as 80 percent. That in turn will probably drive up miles traveled by 60 percent.

“You are talking about a technology that promises to make travel safer, cheaper, more convenient. And when you do that, you’d better expect people are going to do more of it,” MacKenzie said.

The Detroit News