John D. MacDonald 
Cry Hard, Cry Fast 

A gunman on the run, a seventeen-year-old girl on a family vacation, a jaded working girl, a guilt-stricken widower, an abandoned mistress. All heading fast down a route to sudden death. Then for one horrifying instant their lives are frozen in time, when a Cadillac drives at speed into oncoming traffic.Lives are lost, and those that survive must endure a violent sequence of events that ensure life will never be the same again – for any of them.