Originally Posted by
serra
Interesting, I'm not sure how many people would actually stop and let cars on the side go in his example if the main road was about 40 or so mph. Perhaps a better but more expensive solution would be a digital stop sign. It would stay blank when no cars were waiting to get on the main road, and light up as a stop sign when a car was trying to turn on.
I think what you're describing is a stoplight with sensors. Almost all stoplights are like that these days. They could be programmed to switch to flashing red when someone was at the side road, and that's equivalent to a 4 way stop, where people take turns.