Simple solution to speeding

This solution I have is so simple I can’t believe I don’t see it being proposed more often. If too many people are speeding, we can increase the speed limits so that fewer people are driving above the limit.

I would even go further, just let drivers choose the speed, post suggested safe speed for each type of vehicle, everybody stay on the right lane except to pass and most importantly auto manufacturer issues auto insurance covering everything…

Google “85th percentile speed” and you will get plenty of hits.

For example

Traffic engineers already use this idea.


I must be missing something but the speed people drive is a function of the speed limit. On your typical interstate I would guess the 85th percentile is at least 10mph over the posted limit. There would have to be an iterative solution where new speed limits are set in response to new posted limits. Perhaps a stable point would be attained.

You would now have a situation where most people are driving below the posted limit leading to an increased number of cases of road rage. I think I prefer the current system.

Can we do an analogy to all crimes?

Asking for a friend.

I drive rural, midwestern interstates. I think that 5% going 10mph of the posted limit would be about right. Depends on time of day, and day of week.

I’d also guess that most cars are going a few miles over, but staying within the 5 mph rule.

I’m almost always on 70mph roads. How about you?

I’ve been on I-80 in eastern Nebraska a few times recently. The speed limit is 75, the road is great (new pavement, three lanes), but the average speed is not 5mph faster than the average I see on 70mph interstates.

To be serious, I found the change in speed percentiles in 2020 to be fascinating.

In specific, the 1st percentile (and other low percentiles) went up, but not the higher percentiles. Because all the old slow folks were not driving around

I drive the posted speed limit. It’s not hard.

1 Like

This is not true, in my experience. In the northeast, where most of the roads have speed limits of 55mph or 65mph, people tend to drive anywhere from 10 miles over the speed limit to about 80mph, and very few people drive above 80mph.

But I’ve also driven in Arizona, where the speed limit was 80mph. And I found that most people were driving between 70 and 80, just like they did on similar roads in the northeast. Except they were all driving below the speed limit.

I think that 80 is about the max that’s “easy” for a typical driver in a modern car on an interstate-quality road.


I usually drive 10 over the limit if possible on highways, but I max out at about 85. My car gets harder to handle above that.

Personally, I thought the idea of non-newtonian fluid speed bumps was an awesome idea.

If driving behavior is not affected by speed limits, how do you explain this:

Higher Speed Limits Led to More Deaths - Consumer Reports.

In many situations and/or conditions, some people shouldn’t drive the speed limit. If that limit is higher, there are more situations, conditions, and people where driving the speed limit is more dangerous.
Pretty simple. I don’t think behavior changes that much.

1 Like

I guess it depends on how you interpret changing behavior. If you drive 55 when the limit is 55 and 65 when the limit is 65 I would consider that a change in behavior while others would not.

My ex always drove 6 over the speed limit. Always. If the speed limit was 80, he would go 86. Not sure why, and when I asked him to make any sense of it, he couldn’t. I think a lot of people are like him. Maybe not most, but a lot.

This is true in most of the populated areas in the US. It’s even more true in urban areas where some drivers view the left lane(s) as a good spot for birdwatching. On straight highways with little traffic, safe driving over 80 mph is pretty easy where people stay left except to pass.

I have a better solution.

Ban manual cars on the road and go full AV

First sentence is false, as usual. Projecting your incompetent driving on the whole world.

Your second sentence is false, which can be proved by my post since I did no such thing in my post.

You can’t prove that my first sentence is false.

I hate to say it, but you lost this one mister.