21950.(a) The driver of a vehicle shall yield the right-of-way to a pedestrian crossing the roadway within any marked crosswalk or within any unmarked crosswalk…

Under California law, there is such a thing as an “unmarked crosswalk” at nearly any intersection, where pedestrians have just the same legal right of way as they do in a marked one. But a right that you must risk being assaulted or killed to exercise isn’t worth much. Here’s a photo I took the other day on 16th St in San Francisco between X and Potrero Ave. This woman has the right of way, but she’s not acting like it, and I’d be surprised if one driver in 1000 were to yield in this situation:

There are two unmarked crosswalks on this segment. But if you want to cross the street here, you have two choices: you can take your life in your hands, or you can walk an extra 250 years, up and down a steep hill.

I sometimes ride a bike up that same hill. Unless I take the full lane, which requires nerves of steel, some jerk will usually zoom past me with nowhere near the required 3 feet of clearance. (Guess how many citations are issued for violating this law? not many.) It’s terrifying. Just like our pedestrian has the right to cross the street, so too every cyclist has a legal right to use the full lane on this and every street. In practice, they have no such right.

What about speed limits? They’re kind of a sick joke. On the three-lane one-way street in my residential neighborhood, the speed limit is 25. I’ve clocked cars doing 50.

Let’s do a thought experiment. Imagine that all the motor vehicles traveling were autonomous. Now, when the woman steps off the curb at one of those unmarked crosswalks, the traffic in both directions stops and allows her to cross safely. When I take the lane, going up the hill, I won’t be harassed. And no one will speed through my neighborhood at 50mph. Because the software can be made to know and follow the letter of the law.

This is one reason I’m an optimist on self-driving cars and would like to see them become the norm as soon as possible. If we design them to simply follow our existing laws, the constant low-level threat of sudden death for cyclists and pedestrians can be dramatically reduced.

Does this mean we should stop building bike lanes and painting crosswalks and pedestrian refuges? Certainly not. No matter who’s doing the driving, the design of our streets reflects choices about whose interests matter. Autonomous cars won’t change the fact that too-wide streets with fast-moving one-way traffic are stressful, unpleasant, and wasteful.

But if they can just follow the vehicle code, and we can resist the temptation to change those laws to privilege people in cars even further, they can at least make our streets a lot safer while we continue the battle to remake them.