UMTRI: About 87 percent of 19-year-olds in 1983 had their licenses, but more than 30 years later, that percentage had dropped to 69 percent. Other teen driving groups have also declined: 18-year-olds fell from 80 percent in 1983 to 60 percent in 2014, 17-year-olds decreased from 69 percent to 45 percent, and 16-year-olds plummeted from 46 percent to 24 percent.
Cars used to represent freedom. Today WiFi does. The decline of young drivers is likely another reason the roads are getting safer.
Hat tip: @counternotions.
Addendum: Steven Kopits argues (youtube) that this has more to do with lack of employment of young people than with a change in culture.