The number of young people getting drivers licenses is in steady decline
The study, authored by Professor Michael Sivak and researcher Brandon Schoettle of the university's Transportation Research Institute, noted the continuation of a trend among young drivers aged 16-44, who have charted a steady dropoff since at least 1983.
For example, the number of drivers 20-24 has shrunk from 91.8% in 1983 to 76.7% in 2014.
Among 45-69 year olds, the number with licenses increased until a peak sometime in the past ten years, and has since shown a small decrease.
But after increasing significantly from 55% in 1983 to 79.2% in 2011, drivers over 70 have held steady, posting only a .2% decrease in 2014 and maintaining a higher proportion on the road than drivers under 25.
Sivak, who published a similar study in 2011, would not speculate on possible reasons for the trend, but expects his team to test possible reasons in the near future.