A robbery has occurred.

A police officer spots a suspicious-looking person driving near the scene. He follows the car, pulls the driver over and cites him for an illegal lane change. At that point, the officer can investigate the suspect further."Because a traffic arrest is criminal, it allows police officers leeway in investigating other suspected crimes the driver may be involved in," says Sgt. C. Scott Atkinson, Salt Lake City Police Department. "More than 50 percent of drug arrests are the result of initial traffic violations. That also explains why more officers are killed during traffic arrests than any other arrest."

Losing the possibility of threatening a person who runs a red light with a jail sentence doesn't concern Atkinson. "I don't think too many people who commit minor traffic offenses think they'll really end up in jail."

But what does bother him if some traffic laws became civil offenses is possibly losing the authority to pursue further criminal investigation.

But proponents of decriminalizing traffic contend the change from criminal to civil absolutely would not diminish that authority. Officers would have the same privileges they enjoy now. Once someone is pulled over for a traffic violation, the officer could still access statewide computer information listing outstanding warrants and criminal records.