In some U.S. jurisdictions an unpaid infraction can be escalated to a bench warrant. Meaning that no active effort to seek the party involved, however if stopped by police in the area again, have cash to settle the amount or goto jail.

A recent incident at the Peace Arch Border Crossing
 

I'm updating the thread with an excerpt from the Blaine WA Northern Light Police Reports section:

July 20: CBP at Peace Arch port of entry reported a B.C. woman driving while her Washington driver’s privilege is suspended. An officer investigated and determined that the motorist’s Washington driving privileges had been suspended by the state because she had failed to take care of a Blaine police speeding ticket issued in December, 2009. The driver was arrested, cited and released for the DWLS violation. Her licensed passenger took over the driving duties.

Hahaha EXACTLY!! :)