Traffic Lane Width Reduction Improves Safety
I came across this article today by Jeff Speck where he discusses reducing drive lane widths on urban streets from 12′ to 10′. Reading down through the comments there are obviously strong opinions on both sides, but it seems like an obvious safety improvement to me and I think would go a long way to helping create more human-scaled streets here in Sebastopol, and probably many other communities across the country.
You can read the whole article here, but in a nutshell in the article Speck looks at several studies showing that a reduction in lane width leads to reduced accidents, and those accidents that do occur result in less fatalities as cars are generally traveling slower when in 10′ lanes than 12′ lanes. He states people drive at the speed at which they feel safe:
On city streets, most drivers ignore posted speed limits, and instead drive the speed at which they feel safe. That speed is set by the cues provided by the environment. Are there other cars near me? Is an intersection approaching? Can I see around that corner? Are there trees and buildings near the road? Are there people walking or biking nearby? And: How wide is my lane?
28′ wide High St – how fast would you drive here?
I see the difference in how people drive on streets with vastly different lane widths every day. The street I live on is 28′ curb to curb with parallel parking on both sides. With cars parked on both sides you are left with a roughly 14′ travel lane. it’s not a high volume road, but it is used fairly often as it serves as it is a through street as many others in the neighborhood have limited connections. We also have a school at the end of the street so traffic definitely increases before and after school. Given the 14′ travel lane width it’s not comfortable for cars traveling in opposite directions to pass one another. So one car has to ‘give way’ and pull over in between parked cars to let the approaching car pass. The narrow lane width, parked cars, people on the sidewalks, trees and houses with 10′-15′ setbacks are all physical features of the environment that clue drivers to keep their speeds relatively low. Sure there are those that blow through at 30-35 mph from time to time, but generally I would say most people drive less than 25 mph and many drive less than 20 mph because that’s what feels safe.
Looking South on Main Street – How fast would you want to drive here?
In contrast, Main St., which is 1 block away, has 2 one-way travel lanes that are 17′ wide with 8′ parallel parking lanes on both sides (no bike lane, although one is planned which will reduce the lane widths somewhat). Heck, I’d be thankful for a reduction to 12′ here, but 10′ would be even better. The posted speed limit is 25 mph, increasing to 30 about one block to the south for some reason, but drivers regularly speed along here. And why not, with 17′ wide lanes there is a lot of wiggle room before you would move into the adjacent lane or a parked car (and there are often stretches without parked cars, as seen in the photo, which makes the lane feel even wider – effectively 25′ from center stripe to curb). The road is also very straight. There is little to keep you driving at 25 mph other than self-restraint. All visual signals are for you to drive faster than you should. There are several crosswalks with bulb-outs and flashing lights, but drivers often ignore pedestrians waiting to cross.
It’s unfortunate that the 28′ wide street I live on could not be built today (I could not find a copy of the city’s street standards on-line, but I’m pretty sure a 28′ wide street is not in the standards. Certainly not with parking on both sides). The fire department for one would never allow it. They want 20′ clear. To my knowledge no house has burned down, and no one has died because a fire truck or ambulance could not maneuver the street, and it’s been here probably 100 years. But it works very well for keeping car speeds load and pedestrian, bike and car safety high.
This issue is particularly relevant to a blog post I’ve been working on and will hopefully get out next – It’s mostly written but needs some graphics. I have an idea for adding protected bike lanes to Main St. which will reduce lane widths and allow for shorter pedestrian crossings. The idea is to create a more balanced Main Street experience where all users of the public right-of-way pedestrians, bikes, cars and transit may be accommodated. Stay tuned.
