New UK police speed gun can read license plates from half a mile away at night

Most roads aren't sufficiently long and there's plenty of other factors and practical road usage is nowhere near this perfect maximum of safe usage but to point out your mathematical error:

For 10 minutes a section of road 1 mile long has traffic pass through it. The cars have 3 second gaps between them.

At 30 mph: 160 cars max throughput At 60 mph: 180 cars max throughput

In the 30mph example, for the first 2 minutes, 0 cars have completed the 1 mile stretch, for the period 2-10 mins, cars pass the finishing line every 3 seconds. 160 cars complete the 1 mile stretch in 10 mins.

In the 60mph example, only the 1st minute is spent without traffic completing the throughput analysis. For the period 1-10 mins, cars pass the finishing line every 3 seconds. 180 cars complete the 1 mile stretch in 10 mins.

> And if not, I'm sure parliament could pass a law to clear the streets for the day.

My scenario is that we run out of parts due to a foreseen supply chain issue, and parliament can then indeed pass a law to let the delivery guy drive faster, assuming the issue is not fixed.

And for your case, there is already a judicial system that will give you a break if these things happen. In the end, and this is what we really mean to be discussing, rules vs discretion ends up with discretion somewhere in the system.

It isn't wonderful at all. UK has average speed cameras as well and they are horrible. Every time I drive in average speed zones I spend more time looking down because

1) I don't want to go 5mi over the speed limit because I will get fined otherwise 2) I don't want to go 5mi below the speed limit because then drivers behind me have to break one by one which eventually causes a traffic jam 3) I can't overtake a lorry going 65 because it would take me too long and I might miss my exit, which then makes anxious because I have to extend my commute time if I get stuck behind one 4) I can't safely let people merge onto the motorway because if I speed up or slow down then 1) or 2) happen 5) I can't calculate my average speed and to avoid 1) and 2) I have to keep looking down not paying much attention to what's going on around me

This only works on roads with little traffic, like in Scotland, where you can set cruise control and drive for miles. It doesn't work in Cambridge where AADT is ten times higher.

"These systems are safer for police and drivers as there are no traffic stops for speeding."

You are comparing average speed cameras to traffic stops, rather than stationary speed traps...

"Can speed cameras be used as a revenue source? Yes."

No because the primary reason for speed cameras is ensuring road safety, not generating revenue in which case you are encouraging installing speed cameras where they are not required. Speed cameras are not as safe you believe they are, otherwise they would be installed every 100 metres.

"Beyond that, if you don't want to get a fine, don't speed."

That's like saying "if you have nothing to hide, you don't need privacy" using the same "don't do the crime, if you can't do the time" principle, which is flawed. There are plenty of situations where you would want to occasionally speed 10% over the speed limit, but that's not equal to speeding 100% over the speed limit for a very long time. Both will get you a fine. It's not as simple as black or white.

That said, it's also important to use these design techniques for clear reasons. Some people don't like motor vehicles and want to deter their use for reasons other than safety. They have been known to argue for road designs that limit capacity or force traffic to go very slowly as a deterrent measure, when perhaps a road designed to support faster speeds could have been just as safe and allowed a more efficient transport system. Sometimes, they even argue for measures that would likely be counterproductive given their stated goals, possibly without understanding why that would be the result. So before you can design a road, you first need to establish what your requirements are and what you're trying to achieve, which is more of a political question than an engineering one.

Things like that actually happen. Hospital generators fail during a power outage. The floodgate machinery for a dam fails and if they can't get it open in time the dam will burst.

Instances exist of someone without lights and sirens on their car having a legitimate need to get somewhere quickly.

> I could as well make up a scenario where each additional kph increase costs some absurd number of lives, and then it balances wherever you pick the numbers to balance.

But then human discretion is deployed in the other direction, and you don't drive the vehicle that fast, even if the vehicle itself doesn't prevent you from doing so.

> And for your case, there is already a judicial system that will give you a break if these things happen.

What we are discussing is having a chip in your car that prevents you from exceeding the speed limit. How is ex post facto judicial understanding supposed to help with that?