[Someone]

Reading http://www.nsc.org/NewsDocuments/2017/12-month-estimates.pdf, half the increase is due to an increase in vehicle miles travelled, which went up because the USA is coming out of a recession.

[iak8god]

The last recession in the US ended officially ended in 2009. I know the recovery has arguably been sluggish and uneven, but it doesn't seem like the slow & steadily rising GDP over an eight year span should explain much of this shorter-term jump in vehicular deaths.