Slow down, you move too fast.

Former state trooper Lowell Porter, who is now the director of Washington state's Traffic Safety Commission, says that unless trends change, speed will overtake drunk driving as the leading cause of fatal crashes.

Speaking to legislators at NCSL's Strong States, Strong Nation meeting in August, Porter pointed out that traffic crashes are the No. 1 cause of death for people ages 3 to 33, with speed a factor in 31 percent of all fatal crashes.

Unfortunately, the number of police officers hasn't kept up with the number of cars on the road, so to slow people down, states have started using automated speed cameras that hand out tickets. Porter says the cameras have been effective at reducing crashes and fatalities and increasing the ability of law enforcement to keep the roads safe without increasing personnel costs.

In Washington, D.C., and Baltimore, an experiment showed an 86 percent drop in the number of cars going faster than 11 mph over the speed limit in D.C. locations with cameras compared to similar spots in Baltimore without.

A new law in Washington state gives local governments the power to use speed cameras at stoplights in school zones and at railroad crossings to catch red-light runners.

By law, the cameras don't take pictures of the front of the car and the driver, he said, but of the rear of the car and the license plate. Unlike a ticket written by a police officer or state trooper, the speed cameras produce traffic infractions, paid by the car's registered owner instead of the driver. The infraction is processed like a parking ticket and doesn't go on the driver's record.

Porter said barriers to speed-camera systems include the start-up cost and the public perception that "Big Brother is watching you." The cameras use a type of light that doesn't have a visible flash when it takes pictures at night, he said, so some drivers don't know they got caught until they get a ticket in the mail.