The chart shows: The blue line is the number of miles Americans have driven over the preceding 12 months. The green line is collision frequency over the preceding 12 months.
The back story: As people drive more miles, they get in more accidents.
The takeaway: Strong employment numbers mean no respite likely in accident rates.
Sources: Federal Highway Administration; Rolling four-quarter average frequency from Fast Track Monitoring System; Insurance Institute for Highway Safety; Insurance Information Institute.