Anti-Gridlock Laws As An Interesting Edge Case For AI Autonomous Cars

Don’t block the box. If you aren’t familiar with that phrase, you likely have not yet been to a high-traffic locale. The rest of us know that it means staying out of an intersection in a manner to prevent others from being blocked by your presence, almost like playing musical chairs, but with cars, in an intersection, and it is a kind of driving task that seems simple to describe though manages to stymie a lot of drivers.

During my morning commute, I drive through a rather troublesome Los Angeles intersection that I affectionately refer to as the Evil Knievel. I’ve co-opted the name of the famous motorcyclist Evel Knievel that was known for having jumped over numerous cars, buses, live animals, and many other intimidating objects, and well known for his quest to do a motorcycle jump across the Grand Canyon (he instead opted to try jumping across the Snake River Canyon). In all of his myriad of jump variants, he always began with a takeoff point on one side, a leap-of-faith to make the precarious crossing, and then he’d aim to safely land on a landing ramp on the other side. You likely know that he often was unable to make the jumps unscathed and ended-up incurring more than 400+ broken bones and fractures, placing him into the Guinness Book of World Records as the person that survived the most broken bones in a lifetime.

The reason that I invoke this imagery is that the intersection that I cross each day is one that often is prone to gridlock. When I use the word “gridlock” it is meant to suggest that cars will at times enter into the intersection while the light is green and fail to make it fully across the intersection before the light turns red, ending up stranded in the intersection and serving to block traffic. You’ve undoubtedly experienced being blocked by cars that were momentarily stranded in an intersection. And if so, you were probably irked (pissed off!) that those drivers misjudged the situation and are blocking your fully legal efforts to get across the intersection.

Here in California, we are known for having been one of the first states to enact an anti-gridlock law that specifically prohibits the blocking of an intersection, doing so in 1987, and it reads as follows:

“A driver of a vehicle shall not enter an intersection or marked crosswalk unless there is sufficient space on the other side of the intersection or marked crosswalk to accommodate the vehicle driven without obstructing the through passage of vehicles from either side.” California Vehicle Code Section 22526.

The law itself seems rather self-evident and easy to understand. Well, of course you should not enter into an intersection unless you know that you can make it to the other side. Seems pretty simple. Basic driving 101, as they say.  To make things even clearer, many locales refer to this as the “Don’t Block The Box” rule, wherein the intersection is considered to be a box as shaped by the four sides of the respective crosswalks. I suppose that the phrase “anti-gridlock” sounds more formalized and intricate, while the less pedantic notion of just don’t block the intersection box is much more forthright.

Blocking Intersections Is A Temptress

Why did the chicken attempt to cross the road? Because it was hoping to get to the other side, and if it couldn’t do so it figured that being part-way there was better than not any of the way there at all. I think that’s how the old joke goes, though maybe I’ve augmented it a bit. Each morning, I see chickens, uh, make that drivers, whom are seeking to get across the intersection. They can plainly see that there is traffic on the other side of the intersection. They can plainly see that the traffic on the other side is completely choked full and backed-up all the way to the crosswalk. There is no chance of squeezing into that morass. And yet, there are drivers that start into the intersection anyway.

Why do they do so?

One form of logic is that the impatient driver hopes that by the time the light goes red, the traffic on the other side will have moved forward, and therefore they will indeed safely and fully make it across the intersection. They are betting that the traffic up ahead will move on a timely basis to allow them to make it across. Often times these hopeful drivers make a lousy bet and it turns out the traffic up ahead stays put. This means that the driver becomes stranded in the intersection and will be blocking traffic that is trying to next move through the intersection from the perpendicular side.

The cars that are blocked by the interloper are likely to get rather riled-up about the situation. Even if you’ve gotten stuck in the middle of intersection previously, you likely have little sympathy for others that do so. You perhaps were even berated by other drivers when you were in the middle of the intersection, and so you might be inclined to berate other drivers for their similar transgression.

Sometimes the stranded car inspires other drivers to honk their horns at the driver. This used to be a common occurrence in many downtown cities that experience much gridlock. You would hear a continual stream of honking horns due to the continual pattern of cars stuck in the middle of intersections.

In California, we passed a law that says you are only to honk your horn if it will facilitate safe driving. If you opt to use your horn and it is construed by a police officer as not being conducive to safe driving, you can get a ticket for honking your horn.

Is the honking of a horn at a driver that is stranded in the middle of an intersection a form of facilitating safe driving? Likely not. You might try to argue that by honking your horn you are forewarning the stranded driver that they are doing something that is unsafe. I’d expect that a police officer would say that the stranded driver likely already knew that and did not need a honking horn to make them aware of it. You might argue that your horn is aiding other drivers that might not realize the car is stranded in the intersection and thus you are trying to save other drivers. I can imagine the police officer rolling their eyes at that one.

Each morning I see car after car that ends-up in the middle of the intersection and awaits a hopeful chance of making it to the other side. You can see the look in their eyes as they anxiously try to watch the traffic signal and pretend that it will forever remain green, and simultaneously they are looking at the traffic up ahead and praying that it will move forward. Enough cars succeed that it does not always lead to a blocked intersection. The horn honking is relatively minimal, though the frustration level of the other drivers can get pretty high.

There are some drivers that will butt up against the tail-end of the traffic that is on the other side of the intersection. They often are completely covering the crosswalk. They are also likely somewhat protruding into the intersection via the rear portion of their car. This seems like a better spot to be than to be utterly in the middle of the intersection.