I used to live in Los Angeles. On the freeways, the speed limit was 55mph but I read once that the actual average speed was around 17mph.
My (unscientific) theory is that with higher speed limits, you get more traffic waves, and people try to change lanes more often, causing delays.
If the speed limit on LA freeways was only 25mph, I would hope that people would chill out and the traffic would flow more smoothly, resulting in a faster average speed than at present.
Look up "rolling speed harmonization," an attempt to mitigate atrocious traffic to and from the mountains here in Colorado by using a pace car (effectively a strictly-enforced lowered speed limit).
Initial "tests" with lighter traffic conditions proved that the system helped stabilize closing speeds and volume, but in the actually troublesome heavier traffic conditions the state has been unable to figure out when and where to deploy the pace vehicles effectively.
Re:The Lowdown on Lidar
by goodcanadian on Thursday July 31, 2014 @01:19PM
(#8115488)
Be careful with your average speeds. I often drive in excess of 70mph on the (65mph limit) freeway in LA, and I am far from the fastest car. The key difference is that I don't drive in rush hour. A 25mph speed limit would be absurd.
His explanation IIRC was that 1. once people broke the limit it didnt matter how much and 2. when speed limits felt more correct more people respected them.
I'd love to know if anyone has any pointers to research on this as around here speed limits are weird. (80 in places where you obviously can't even drive 80 and 80 on the highway, -four lanes)