The thing is… You don’t really need to stop for a full three seconds… but you have got to stop.

It takes no more than a second to verify that nobody is coming and it’s safe to proceed, and that’s if you weren’t looking around as you approached the sign, or you couldn’t see oncoming traffic until you were at the line. I once read a very frightening comment that said it takes four seconds to check in your mirror to change lanes. I’d rather not be on the road with someone who needs four seconds to answer a binary question eg, is someone there or not.

And I’d go so far as to say that one can sometimes safely do a slow roll through a stop sign. When it’s a four-way stop, all directions are easily visible, and nobody is within a hundred yards, no harm no foul, I always say. I’ll go even further and say that if you stop a full three seconds at an intersection with good visibility and a four way stop, I will think poorly of you.

But as with all rules of the road, the thing to think about is: why is this rule in place? With stop signs there are a few possibilities.

When a street is at all busy, you want to allow people on cross-streets to safely navigate the intersections. This is the main reason you’ll see them. I got a stop sign put up in San Francisco for safety purposes. If there are a lot of accidents at an intersection, they’ll probably want to put a stop sign up; or if there is a two-way stop they might change it to a four way.

Another possible reason is traffic calming. If a street is nice and long, connects one neighborhood to another, that sort of thing, people will be tempted to speed. Planners will often try adding a stop sign before putting in speed bumps.

Now the key safety thing to consider is whether it’s a four-way (sometimes “all-way”) or a two-way sign. You need to be more cautious with the two-way signs. If you come to a sign and it is not a four-way, you are in danger of being nailed if you don’t stop to look out.

It is especially important to keep in mind that people run stop signs sometimes. It’s not a wall that goes up to keep them from proceeding (though that’s an interesting idea!). You should always maintain awareness of your surroundings while driving (and probably while not driving).

And the final thing to be aware of with stop signs is that you’ll find them almost exclusively in residential areas (sometimes when exiting them). There are some odd exceptions, but mainly it’s residential. This means that you should be driving at a top speed of 25MPH and be prepared to stop at any time. Any place you see a stop sign, you have the risk of pedestrians in the road.

Stop signs are like a lot of the rules of the road: obvious and intended for safety. If you can’t stop at stop signs, I do not want to share the road with you. Can I interest you in public transportation?