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Comment by pclmulqdq | Hacker News Reader

And raising speed limits where appropriate. US speed limits right now are often set at about the right level on urban and suburban roads, but far too low on highways and other roads intended for long-distance travel. This effectively causes people to speed at dangerous levels in the suburbs and cities - it does not slow everyone down everywhere.

Edit: The statement "speed limits are about right" does not mean "current travel speeds are about right." If you read the rest of the comment, it means that current travel speeds are about 5-10 mph too fast for most roads, but you don't actually need to change any signs if you start making speed limits a credible fact about the actual speed limit of the road.

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I'm very curious where your data comes from to back up this statement. "The current level of pedestrian fatalities from motor vehicle collisions is the right level" just seems wrong to me.

I never said that. Go back and read closely.

The obviously-too-low speed limits cause all speed limits to be called into question. Thus, Americans drive about 10 mph over the limit on suburban roads, where lots of fatalities occur, and the opinion that speed limits are too low is very common. Also, significant data exists that shows that the vast majority of fatalities involve a driver that is speeding.

I’m curious. Do you have data to back this up?

Of course not. “Speeds are correct on non-highways” doesn’t match the level of pedestrian fatalities in the US. He might be 100% correct about the highway speed, though I doubt it, since most highways (interstate/limited access) seem to be 65 or 70, except in urban areas.

It's a good thing that the pedestrian fatalities you are trying to cite very often happen due to someone speeding (that is a fact that you can corroborate with police data if you would like). If people don't obey a speed limit, you can't cite a consequence of their driving speed to say that the limit is too high.

Also, I have exactly as much data as everyone else is bringing to this discussion, including you and the GP comment, who have brought no relevant data either. This is just my opinion.

You’re the one who made the contention that suburban/non-highway speeds are just fine, despite high levels of pedestrian/non-car injury/death, not me.

And yes, I can absolutely say speed limits are too high, even if people are exceeding them. People drive the speed they feel safe, not the speed we want. So, we should design the roads to ensure people drive the speeds we want.

IE, a wide open 4-lane road is going to see speeds above 40mph, even if it’s posted at 20mph. Because it looks/feels safe from within a car. Yet, we keep building wide open 4-lane roads and wondering why everybody speeds and people keep getting run over.

I never said speeds are just fine. I said speed limits are fine, but being flagrantly violated. And yes, I agree that road design plays into this.

My experience with the design of many roads suggests that people generally take them far too fast regardless: they cut corners, don't stay fully in their lane, and do lots of other things that indicate they are driving far too fast.

Just anecdotally, I’ve experienced the same. The speed of traffic on highways is regularly 5-25 mph above the limit, and this mindset does translate to other types of road.

Do you have any data to contradict this? The statement you are asking for data about is an opinion, and asking for data to back up an opinion is at best a logical fallacy.

However, if you want to know how I got my opinion, I would suggest that you look at NYC, which has almost eliminated pedestrian fatalities by heavily enforcing its 25 MPH speed limit and similar traffic laws. Conversely, most drivers I see in suburban areas drive at least 5 MPH over the speed limit.

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