Here’s an article arguing compellingly for 10-foot lanes on city streets. 12-foot lanes might save time and lives on highways, but on city streets they waste space and kill people.

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?

All of these factors matter, and others, too. The simplest one to discuss, and probably the most impactful, is lane width. When lanes are built too wide, many bad things happen. In a sentence: pedestrians are forced to walk further across streets on which cars are moving too fast and bikes don’t fit.

I think we need to move toward safe, multi-modal streets on the Dutch and Danish models worldwide. This will be truly sustainable – safe, healthy, low-energy, low-carbon, and supportive of creative, innovative urban ecosystems where people can come together to solve problems. These are major capital investments with tax dollars, so a cost-effective way to do them is to develop the new standards, adopt them as business as usual, and then upgrade our streets to the new standards as they wear out.

That is a vision, but I see some cheap, easy short-term retrofits that could be done right away without major capital investment. Repainting with narrower lanes (streets need to be painted periodically anyway), and giving the saved space to pedestrians, bicycles, and green infrastructure would be pretty easy. Once streets get repainted, the next incremental step is bollards or other physical protections for pedestrians and cyclists. Some more short-term parking and loading zones would be helpful in a lot of cities – if we had more of those in Philadelphia you wouldn’t have so many people blocking the bike lanes we do have. Another short-term thing that could be done is to turn off stoplights and go back to stop signs on a lot of lower-traffic streets – this should even save a little energy and money. Stop signs are much safer for pedestrians, because all the vehicles have to stop or at least almost stop. You don’t have people gunning the engine on a yellow light to clear the intersection or make a quick turn – that is when pedestrians and cyclists die. Finally, on higher-traffic streets, light signals can be reprogrammed so that pedestrians are not in conflict with cars. Left turns on green just absolutely have to go away. I think right turns on green can be made a lot safer by  small curb extension requiring a sharper turn, but we should think seriously about whether we want any turns on green. Let’s think about the pedestrian scramble model, where all traffic stops and pedestrians can cross diagonally. Cyclists could be allowed to treat this like a stop sign. Then, add turn arrows for all turns and it’s pretty safe for everyone.