The "road diet" on Fauntleroy Way in West Seattle was controversial when it was introduced, to say the least: Drivers, used to being able to speed along four general-purpose traffic lanes, feared that reducing the road to two traffic lanes, a turn lane, and a lane for cyclists would lead to total gridlock and chaos (sample comment from the West Seattle Blog: "They want to inconvenience 95 percent of the people who drive on Fauntleroy Way for the 5 percent who use bicycles? This can’t be allowed").

Well, the data is in, and it turns out, the doomsayers were (once again) wrong.

How wrong? SDOT's data show that the road diet has dramatically reduced collisions and reduced speeding in general on that corridor. The total number of collisions went down 31 percent after the road was striped for bike lanes and given a center turn lane, and collisions resulting in an injury went down 73 percent. Collisions between cars and cyclists went down to zero.

Speeding went down, too. According to SDOT, the number of drivers driving over the speed limit declined 7 percent, while the number of drivers going more than 10 mph over the speed limit declined a whopping 13 percent. Those downward trends took place even as traffic volumes increased, on average, 0.2 percent.

But the real story, for drivers anyway, may be that travel times barely increased at all. During morning rush hour, the time to get from Alaska to California on Fauntleroy increased four seconds southbound and 45 seconds northbound. During the afternoon rush hour, travel times increased 76 seconds southbound and five seconds northbound.

Road diets, in other words, work---improving safety for pedestrians and cyclists and calming traffic while keeping car traffic moving smoothly. That isn't pro-cycling, anti-car propaganda talking; it's hard facts, based on a year's worth of traffic data. One of these days, the anti-bike-lane forces will have to start listening.