In part two of this short series about Portland’s biking infrastructure, and how it lets you ride bikes without the need to be a bad ass all the time, we’ll look at a proposal by the Portland Bureau of Transportation (PBOT) to lower the speed limits on their bike boulevards to 20 mph.

Bike Portland reported yesterday that the city is proposing changes to Oregon state law in their legislative agenda that would allow the city to lower the speed limit on all “neighborhood greenways.” One potential problem with bike boulevards, especially when the stop signs are removed, is that they allow cars to travel quickly on those roads if they want to. I did not experience this while I was there this past weekend, but apparently it happens.

To counter this, the city has been installing speed bumps and creates limitations to arterial road access by cars. Lowering the speeds on these streets to 20 mph would help improve safety on these streets by providing one more incentive for drivers to use a different street if they can.

I’ve written is support of 20 mph neighborhood speed limits before, and I feel like Seattle would be welcoming to this easy, cheap change. Or maybe there could be an easy public process where neighborhoods could apply to have their residential street speed limits lowered if they desire it.

The statistics on car-pedestrian collisions are stunning. The odds of a pedestrian dying after being struck by a car going 20 mph is 5 percent. The odds at 30 mph jump to around 40 percent. Lowering average speeds closer to 20 would dramatically increase safety on residential streets while adding negligible time to car trips.

That seems like a no-brainer change that could generate a lot of good discussion about the importance of driving safely on residential streets.