On: The Irresistible Urge to Build Cities from Scratch

[umichguy]

That's kind of stupid...takes the point away from roundabouts. They're designed to keep the traffic flowing in low /medium conditions when a traffic light or stop sign would bring it to a halt otherwise. Saves on fuel etc.

[bmsleight_ → umichguy]

Above a flow of around 3,600 pcu/hr (passenger car units) per lane, the roundabouts does not balance each direction effectively. (No gaps).

Traffic lights (signals), can help improve flow further in these situations as well as giving pedestrians a safe way to cross.

Part-time signals (only on a peak) can be very effective.

[village-idiot → bmsleight_]

These areas are way below 3,600 pcu/h, maybe down in the several hundred to a thousand area. We’re talking residential side streets.

[village-idiot → umichguy]

You have no idea how frustrated they make me.