What you are talking about is the so-called "Solomon Curve". This if oft-quoted research which seems to show that slower moving drivers in a rural highway type situation have far more crashes than those driving with the flow of traffic and even those driving a fair bit faster than average.

There are three basic problems with this, however:

- It is research on rural highway and freeway type situations that applies only that that particular situation. We might all agree that driving 25 mph on an 80 mph freeway is best to be avoided, if you can. But it has literally no application to streets and roads in a town or city - that's not where any of the data behind the Solomon Curve came from.

- The researchers did not separate out turning situations from the "slow driver" situation, which is the one we are talking about here. Turning and crossing movements are disproportionately represented in rural highway crashes - people are usually going quite slow during turns.

It's the turning part that increases the risk of collisions, though - not the slow speed. Solomon massively skewed his research by including all these turning drivers and classifying them as "slow drivers".

- More recent and careful research has rather definitely overturned the "Solomon Curve".

Here is decent research summary that makes all the same basic points I did in my two comments above, but backs them with citations and evidence, and also tackles the Solomon Curve "are slow drivers dangerous?" issue:

https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa1304/Resources3/08%20-%20The%20Relation%20Between%20Speed%20and%20Crashes.pdf

Regarding the supposed high crash risk of slow driving, it says:

>The first studies of this type were conducted in the United States in the 1950s and 1960s, e.g. Solomon (1964). These studies always found a U-curve: the slower or faster a car drives compared with most of the vehicles on that road, the more the risk of being involved in a crash increased.
>
>However, more recent studies, especially those carried out in Australia (e.g. Kloeden et al., 1997; 2001; 2002) that used more modern measuring instruments and used a more accurate research design, reached a different conclusion. They still indicate that vehicles that drive faster than average on that road have a higher crash rate; vehicles that drive slower, however, were found not to have an increased risk (Figure 3).

Figure 3 is worth taking a look at. For rural roads, it shows:

- Slightly lower crash risk for those traveling slower than average.

- Slightly higher crash risk for those traveling faster than average

For urban roads, the situation is somewhat different:

- Still slightly lower crash risk for those traveling slower than average.

- However, massively higher crash risk for those traveling much faster than average.

If you're going say 5mph faster than average, the crash risk just just a bit higher - about what you'd expect.

But drive 10-15 mph faster than the average speed and now we're talking 10X-30X increased crash risk.

FOAD.

I do very little driving period, because it's a fool's game from just about every angle. But when I do, I go whatever speed I need to to be safe and it's your job to do the same literally no matter what speed other people are driving. Or walking or biking or carting or whatever it is they do.

There is literally no minimum speed limit in Missouri and if you think there is or should be then you are the problem, not people who, for whatever reason, want or need to go slower as is their perfect legal right.

A surprise to many, but going as fast as you want in your car is not a constitutionally protected right.

But exercising the highest degree of care towards other drivers and everyone else on the road whenever you drive is in fact your legal duty.

>NAVIGATING THE ROADS AT OR NEAR THE POSTED SPEED LIMIT

I will just mention that there is no minimum speed limit on the vast majority of roads in Missouri (the one exception is interstate freeways, which have a marked minimum speed limit).

In all other places, it is completely incumbent on any and every driver to assume that there might be people driving - or bicycling, scootering, tractoring, mail-delivering, horse-drawn carting or doing any of any of 10 dozen other perfectly legal and normal things - at anywhere from 1 mph up to the speed limit.

Someone driving at 10mph or 20 mph on the road is not and should not be especially dangerous and it is not especially unusual. Farm tractors and other farm equipment will drive miles down the road at 10mph or so and everyone just deals with it. It is not illegal and also not especially dangerous.

Especially now that you know, and you are going to drive from here on out with that in the forefront of your mind.

Also, I will point out Missouri law that most drivers like to forget:

>Every person operating a motor vehicle on the roads and highways of this state shall drive the vehicle in a careful and prudent manner and at a rate of speed so as not to endanger the property of another or the life or limb of any person and shall exercise the highest degree of care. 304.012 RSMo

As a motor vehicle driver, you must drive at all times with the highest degree of care.

That is a might high bar.

That means, among other things, that you are driving at all times as though someone may be stopped, or going 10mph, or 20 mph, over any given hill or around any given curve, or at any intersection.

That means, that with the degree of safe driving that you are doing, that those 20mph elderly drivers are in absolutely no danger at all from you, because you are anticipating them and the fact that they - or anyone else - might be going that speed.

Also I will point out, that you will probably want to point out that the slow driver is breaking this law as their super-slow speed is "a rate of speed so as ... to endanger the property of another or the life or limb of any person". This is absolutely wrong and the courts have never held it to mean this. They have, on the contrary, held that there is no minimum speed limit unless that is specifically set.

And what they have held is that driving too fast for conditions - even if under the stated speed limit - is not legal if driving at that too-fast speed endangers others.

Finally I will point out that too-fast driving is responsible for or substantially contributes to a large amount of our traffic deaths and serious injuries. But too-slow driving is such a non-problem as far as traffic safety that no one even bothers to track fatalities and injuries related to it.

High driving speed is a quadruple whammy, as events happen too fast for people to observe and react to, once you do notice something amiss the time for you to react is much shorter, once you do react the high speed makes it much harder to maneuver or brake in time to avoid a crash, and when you do crash higher speeds mean more damage and higher injuries.

Not only are higher speeds worse on all four of those factors, but in fact the problem in each of those four areas grow exponentially with speed. Going twice as fast is not just twice as dangerous, but more like 4X.

More details/research: https://nacto.org/publication/city-limits/the-need/speed-kills