A Dutch engineer once told me (back before 2004 I guess ) that they once raised the speed limit on the roads in Netherlands only to find average speed decreased.

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)

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.

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.

Speeding is extremely dangerous. It's ludicrous to argue otherwise. A third of crashes (including fatal crashes) involve speeding, and the faster you are driving the more likely you are to die or fatally injure another.

Also, changing the speed limits on roads have been studied and it doesn't make a humongous difference. The government usually sets the speed limit at slightly lower than the average speed people actually drive.

> Speeding is extremely dangerous. It's ludicrous to argue otherwise.

Actually, blanket arguments like "speeding is extremely dangerous" are ludicrous. "Speeding" is exceeding a semi-arbitrary speed threshold. If that threshold is, say, 70 mph I'm OK at 70 but if I go to 71 I am being "extremely dangerous"? 71 is speeding in that case, after all.

> A third of crashes (including fatal crashes) involve speeding,

If a third or more of all drivers speed, that statistic is meaningless.

> the faster you are driving the more likely you are to die or fatally injure another.

Indeed, and that statement has nothing to do with speeding. It is a continuum from 0 to whatever the top speed of a given vehicle is. This statement is equally valid when you are under the speed limit.

> Also, changing the speed limits on roads have been studied and it doesn't make a humongous difference. The government usually sets the speed limit at slightly lower than the average speed people actually drive.

I have seen that happen before, but in my experience that is the exception rather than the rule.

A third of people driving are speeding.

"The government usually sets the speed limit at slightly lower than the average speed people actually drive."

I don't think you've ever driven on a US interstate.

> the current limits on most roads don't represent what speed ... people could safely drive at.

If there's a sidewalk or any t-junctions, that's about 20mph tops. Anything faster, and you can't stop in time, plus in a collision, kinetic energy goes as the square of the speed.

For local trips, with stoplights that slow you down anyway, driving slower adds only a few extra minutes to your journey time. Personally, I'm not seeing the need to be so hurried all the time.

http://www.rospa.com/roadsafety/adviceandinformation/driving... http://blog.americansafetycouncil.com/why-speeding-is-danger...

I think the GP is talking about speed limits on controlled-access highways, not on residential or commercial streets.