How strictly should speed limits be enforced?

Yesterday at a social gathering I found myself talking with a police officer in our town. We discussed speed limits. On one sorta major road, he said the speed limit was 30 MPH. (I can pretty much guarantee I’ve NEVER driven that slowly on that road.). He said they have no guidance as to the speed at which they should write tickets. He generally does it at 15 over, and most others do at least 10 over.

Another guy found that very bothersome. He thought the limit should be set at whatever is an appropriate level, and strictly enforced. If no cop writes tickets under 40, the limit should be at least 40.

Or on the expressway. Some have limits of 55, but anyone going 55 would cnstitute a traffic hazard, as essentially no one goes slower than 65 and most go 70+.

I found that I had no strong opinions, but could see merits of either approach. What do you folk think?

Ticket at > speed limit.
Otherwise, it’s just a “suggestion.”

From a “nation of laws, not of men” perspective @beowulff nailed it in one.

From the “large rights of the people overcome the limited rights of government” perspective the limits (if they should exist at all) should be set by reference to the collective behavior of the drivers. In a real sense each of us votes every day for what the limit ought to be on any and every road we traverse. As the saying almost goes, we “vote with our (right) feet.”

In that understanding the “limit” is not what the median driver does. Nor the mode nor the average. It’s also not what the most extreme leadfooted outlier does.

IMO the “limit” is, or ought to be, that speed where substantially everyone observing somebody going that fast says “That’s too much.” That is the point community norms are unequivocally violated. And what basis is there for any law on any topic but community norms?

There are issues because speedometers are not 100% accurate but not that inaccurate.

In the UK the National Police Chiefs’ Council (NPCC) urges police officers to use their discretion when dealing with drivers who break the speed limit. To be more specific, they recommend only handing out speeding tickets if a driver surpasses the speed limit by 10% plus 2.

The logic is if you are doing 34 in a 30 limit your speedo might be reading 30 (Though in my experience speedos tend to underestimate speed rather than overestimate). There is also a need to keep public confidence, if you are trying to drive at 30mph it is very easy to mementarily hit 31 and if that is when you go through a speed camera someone who gets fined for such an infraction is likely to blame the police being jobsworths or revenue collectors rather than being primarily concerned with safety.

Driving behavior here varies between people who tend to stick to the limit and those that rely on the 10%+2 leniancy, the odds of getting stopped if you go over that is pretty high.

Penalties depend on how far you far over the limit, driving over 40 in a 30 limit gets you in the 2nd tier with higher fines, more penalty points and possibly a ban. We do’t have 55 limits here but doing more than 80 in a 60 limit is also going into the second tier of speeding offences.

Enforcing it right on isn’t practical. Traffic often winds up going a bit faster than the speed limit, situationally, or just as a matter of course. And speedometers and radar guns are not exact.

People don’t tend to treat speed limits like some sort of upper limit, but more the speed to aim for on that road. And I’m pretty sure roads are built with that in mind–the maximum safe speed isn’t really 55 mph.

It is infrequent that I find myself driving at the speed limit. (Well, often, I don’t even know what the limit is, as it seems to be irregularly posted.) Most of the time I - as well as traffic - move at least 5 MPH over the limit. Some roads, traffic moves closer to 15 over. Quite often - as on the road in question - the speed limit impresses me as WAY too low.

So do the folk who advocate strict enforcement suggest limits be increased? Or that traffic slow?

The more I think of it, it is challenging to set a single speed limit that is appropriate for all times of day/weather conditions/traffic levels…

Yeah I’m in agreement with this guy. Basically whenever you have a law that is widely flouted and left up to the discretion of the cops, it really only a law for non-white poor people, not for white rich people.

I would put money on the fact that if you actually study this and work out who gets pulled over at what speed, the average non-white person driving a cheap banged up looking old model car would be pulled over at the 10mph or lower level whereas a white guy in a pristine new SUV would be at the 15mph+ level.

So, would you guys support radar cameras issuing tickets automatically to everyone 1 MPH over?

10% over. At 70, you can go 77, and in a 15 mph school zone, you’re at 16.5.

So…somewhere in between?

Yup, I’ve been wondering this lately, myself. Any time when you have a law that’s not usually enforced, there’s the opportunity for selective enforcement, only against whomever law enforcement doesn’t like. And that’s never a good thing.

I’d like to see if there’s any data on race and speeding tickets.

Speed limits are generally too slow, and that’s probably why many officers give a 10 mph leeway. To me, at least, speed should be dependent upon conditions such as weather, traffic density, proper lane usage, etc.

On I-294, for example, morning traffic flows at 80 mph even though the official speed limit is 65. If no one is weaving in or out or going noticeably faster, there is no problem, so why write a ticket? I’d much rather see tickets written for unsafe driving practices no matter what the speed.

That and linked discussions seem odd. I had assumed limits were set at a level deemed “safe” - maybe based on number of cross streets/driveways, road width, number of lanes, bends/hills, visual obstructions, traffic density, proximity of pedestrians… It never crossed my mind that it was calculated based on measuring how fast people were actually driving…

The road I’m discussing is North Ave (64) in Elmhurst, IL. It is a pretty main E-W thoroughfare from Lake Michigan for more than 30 miles to the west.

The stretch through Elmhurst is more residential compared to the stretches immediately east or west. People coming to the stretch from either direction would likely have been driving much faster than 30.

By comparison, the limit on much smaller, solely residential streets in town is 25 - only 5 MPH slower than on this major thru street.

That’s pretty much what I think.

And, yeah - as with much/most law enforcement in the US, I’d expect there to be racial disparities. I doubt there are stats for our mostly white town. But I can’t recall having ever seen non-automated traffic stop stats that did NOT reflect such disparity.

I note, unless you advocate automatic, universal ticketing, there will always be the possibility of selective enforcement.

Choosing to arbitrarily enforce a 40 mph speed limit at 40.000001 mph is just as silly as the process that set such a limit, given that normal traffic naturally settles in at a much higher speed.

That being said, I think some better questions would be:

  • How can we enforce speeds in a way that doesn’t inevitably bleed over into a revenue generation scheme?

  • While speeds are correlated with higher fatalities, it’s speed differentials (AIUI) that correlate with more accidents occurring. Assuming that’s true, how can we make traffic flow more smoothly and safely?

  • Aren’t we really enforcing speeds simply because it’s the most easily measured aspect of driving? I see a metric s**t ton of poor driving behavior every day that has little to do with speed. Things like slow drivers in the left lane forcing people to pass unsafely on the right, and lots of pure inattentiveness. How can we better police that sort of behavior rather than just speed?

I’d be fine with that, as long as not a penny of the fine goes to the police force or municipality that installed the camera.

The accumulation of (detrimental) points on your record is one non-revenue solution. If you get a few points, your insurance will go up. If you get a lot of points, your license gets suspended. If you drive without a license, you get jail time.

Remedial driving classes are another (mostly) non-revenue answer. If you have to come in and waste four hours on a Saturday morning, you might think twice about doing something stupid behind the wheel the next time. And you better pay attention during class, because a failing grade on the final exam could mean you end up having to take (and pay for) a road test. Course costs could be covered by a fee assessed to the violator as part of the citation. Wouldn’t be much, if you’ve got one instructor handling a class with a dozen or more people in it .

Punitive fines can still be a part of the solution, but any revenue collected should not be seen to have a significant impact on the issuing department’s budget. For citations issued by municipal police forces, the revenue should go to the state treasury. For citations issued by state police forces, the revenue should go the US treasury.

If you are driving above the speed limit, and also doing something else that is illegal or unsafe, like not obeying other traffic laws, driving erratically, driving significantly faster than other traffic, etc., that’s when I’d give you a ticket.

As others have mentioned, a “safe” speed depends on lots of factors.

And driving above the speed limit is usually safe, but it makes it more dangerous if something unexpected happens (e.g. something in the road ahead).

Driving cross-country in some southwestern state—I think Arizona?—I found my route took me along a very straight sub-highway, about 30 miles long, in the middle of nowhere, whose sole purpose was to get you from one major highway to another.

Because of this, there was obviously a strong temptation for drivers to race along it at top speed. And so what they did was post lots of signage strongly emphasizing that the speed limit was 60. Exactly 60. No negotiation, strictly enforced. Even the cashier at the gas station I stopped at just before getting on took pains to warn me about it, recommending I use cruise control if I had it—I did—to make sure my speed was exactly 60.

So I got on with some trepidation: “Man, they must be real hard-asses around here.”

But you know what? It was awesome. No worrying about flow of traffic vs speed limit, people jockeying for lanes, tailgating, flashing headlights—everyone on the road agreed on the proper speed and that was that.

I hadn’t until then consciously realized how much of my driving brain was normally engaged with constantly worrying about my speed!

That’s what I find it’s like driving on major motorways in the UK – pretty much everyone going the exact same speed, the speed limit, due to all the cameras.