Drivers with out-of-state plates are much more likely to be stopped by Iowa State Patrol when they drive across the state.
The Des Moines Register reviewed about 22,000 traffic warnings and tickets issued by the State Patrol between 2008 and the end of last year.
About 86 percent of those tickets and warnings went to out-of-state drivers.
Some lawyers and motorists question whether or not the State Patrol's interest in out-of-state drivers is warranted, and they say troopers sometimes use minor offenses to conduct questionable interrogations.
But officials defend the State Patrol's practices and say the state where a car is from is only one factor considered. Sgt. Rob Mordini says troopers are also looking for suspicious behavior on the part of drivers.