- Albuquerque and Portland use red lights to reward drivers who obey limits. - Portland says one pilot cut average speeds from 39 mph to the 30 mph limit. - City says the system helped reduce crashes and injuries on one corridor. All of us want to get where we’re going quickly and safely. Oftentimes, those two factors can be at odds. Two states are testing out a way for both to work in harmony. If drivers slow down to the speed limit, they’re sometimes granted more green lights. That means a quicker overall commute despite driving at a lower top speed, and the data indicates that the system is working. Albuquerque, New Mexico, and Portland, Oregon, are using variations of a traffic-signal strategy known as “rest in red.” Instead of leaving a light green when nobody is around, the signal defaults to red. Sensors detect approaching vehicles and, crucially, how quickly they’re traveling. Obey the speed limit, and you can get an earlier green. Read: Over 20% Of San Diego Roads Could Get Lower Speed Limits Overnight Come barreling toward the intersection, and you’re more likely to sit there. In other words, it’s effectively a speed camera that doesn’t mail you a ticket. The idea has been particularly useful on roads that carry plenty of traffic during the day but become tempting improvised drag strips after dark. Portland calls the concept a “virtual speed bump.” What Happened On One Of Portland’s Worst Streets Portland runs the system on stretches of Southeast Powell Boulevard, one of the city’s highest-crash corridors, mostly between 10 p.m. and 6 a.m. or 7 a.m. depending on the day. City officials told The AP that average speeds at the first intersection tested dropped from 39 mph (63 km/h) to the posted 30 mph (48 km/h).