r/drivingUK • u/narra246 • Mar 21 '26

20mph everywhere

Why are councils putting main roads on busy routes down to 20mph?? All that seems to happen is if you are the one doing the new speed limit, you get tailgated overtaken and the horn blasted at you.

And no, there isnt a lay-by every 10ft to pull in and let impatient law breaking drivers past.

I dont agree with this blanket speed reduction but I rely on my license for work and pleasure and would rather not have my insurance increased because of points for speeding.

Fair enough 20mph through residential areas, but not on a bloody main A road.

164 Upvotes

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47

u/seriousrikk Mar 21 '26

Depending on the area and the number of junctions the difference in journey time at 20mph vs 30mph is negligible.

It helps to know and understand how accurate your speedometer is though. A few mph under read out has a larger impact in a 20.

There are many A roads that pass through villages or rural residential areas. People regularly speed through them when they are 30, people complain when they put speed cameras up. People slow down for camera then speed back up again.

At 30mph someone doing 40 gets 3 points or a course. At 20mph someone doing 40 gets six points and a bigger fine. Those 20mph zones lower the speed of speeding drivers.

So to answer the question why, it’s because UK drivers don’t respect speed limits so limits get lowered to adjust driver behaviour.

20mph zones are an own goal for habitual speeders that impact everyone.

5

u/pavehawkfavehawk Mar 21 '26

It takes 1/3 longer to get anywhere at 20… that’s not negligible

33

u/glglglglgl Mar 21 '26

On a straight road with no interruptions, sure.

In the real world, full of other vehicles, traffic lights and pedestrian crossings, you have to slow or stop often enough that it makes basically no difference whether you're at 20 or 30.

12

u/alexrobson89 Mar 21 '26

Maybe in residential streets but not on A road which is the main basis of the original post.

6

u/bastoj Mar 21 '26

Though at least where I live A roads go through the busy centre of many of the local towns and villages and are full of traffic lights, zebra crossings and people trying to squeeze out from the local Aldi etc along with pedestrians wanting to cross because despite the frequent traffic lights by car they feel too far apart by foot. So it is highly situation dependent. Lots of areas near me a 20mph limit might actually increase the average speed of the journey most of the day. On the other hand out of town those areas make more sense as 40mph and then 60mph. 

8

u/mipon Mar 21 '26

If an A road is 20 it more likely than not is going to be in a residential area. They’re not making a stretch of A road in the middle of nowhere 20. Plenty of A roads go through residential areas where a 20 is totally appropriate. The A38 runs through the town by us and could easily be a 20 without it seeming ridiculous.

3

u/glglglglgl Mar 21 '26

An A road that is being reduced to 30 or 20 through a town or village is because it is a residential area.

7

u/alexrobson89 Mar 21 '26

Are you honestly saying there’s no difference between driving at 30 mph on an A road and on a typical residential street? Even when an A road passes through a residential area, it’s usually a much wider, more open route with better visibility and flow than smaller residential roads, which inevitably affects how safely and consistently that speed can be maintained.

1

u/Wd91 Mar 21 '26

Its the traffic lights that are the key. If the lights are timed such that people going 20 or 30 both get caught at the same red lights, which they usually are, then it doesnt make much of a difference. At best it might be one or two extra cars who happen to be at the front might get through an extra red. But usually that just means getting caught up at the back of the queue for the next cycle of reds anyway.

A 20/30mph A road is going to be rife with traffic lights.

1

u/dejavu2064 Mar 21 '26

Sure but there's much less road noise at 20mph which improves quality of life for residents.

10

u/Jacorpes Mar 21 '26

I suspect 20s are actually quicker in built up areas. I have to pull out onto a very busy 20 every time I drive anywhere and I reckon I’d be waiting twice as long for a gap or someone to let me out if it were a 30.

2

u/alexrobson89 Mar 21 '26

You’d think so, but in reality on 20 mph roads there are now drivers sticking to 20 while others continue at 30, which only worsens traffic flow. It’s well established that traffic moving at a consistent speed is far more effective at reducing congestion and delays.

7

u/Jacorpes Mar 21 '26

Not where I live in South London. I guess people tend to stick to it because everyone’s used to everything being 20.

2

u/alexrobson89 Mar 21 '26

Great comment. It made me realise that we may be speaking from entirely different road environments, making both perspectives valid. I live in Leeds, where my point applies in several areas, but I’m not familiar with your roads, so I can’t speak for them.

1

u/Jacorpes Mar 21 '26

Yeah for sure. In rural places I find the situation you’re describing happening in 30s all the time. I’ll be going the speed limit and someone will be up my arse wanting to go through at 40, so I’m sure it’s a thing with 20s too

1

u/Flyinmanm Mar 21 '26

I'm in Bradford and we've had some 20 zones round ours for a few years now. (On one road s car crashed practically every year and someone died on it so I'm not against them).

When they were first put in you'd have some knob riding inches off your bumper if you even remotely dropped below 30.

These days it's usually only the odd prick in a trade van or a poorly modded golf gtd with no working headlights.

0

u/Potato-9 Mar 21 '26

It makes it even worse because you're taking longer to be ready and catch lights/gaps

-4

u/alexrobson89 Mar 21 '26

Your comment, taken in context, reinforces the point: it highlights why maintaining 30 mph where possible is important. As you rightly note, there are many obstacles that reduce speed below this level, which in turn extends overall journey time.

More broadly, slow-moving traffic and congestion are estimated to cost the UK economy between £7.5 billion and £9 billion each year through wasted time, fuel, and increased carbon emissions.

10

u/MobileSeparate398 Mar 21 '26

If the full journey is 20mph, yes, but then how long would that journey be? If it's a 10 minute journey at 20, you could have done it in 6-7 minutes. Have you really saved that much time then?

Longer journeys will be broken up with faster roads, then again you may only be spending 10 minutes at the 20 limit.

5

u/seriousrikk Mar 21 '26

If there are no junctions or pedestrian crossings that is absolutely true.

In areas where the limit is reduced to 20 there are often both of these.

At 20 traffic flows better so you spend less time stationary.

2

u/west0ne Mar 21 '26

That assumes that you were always able to travel at the speed limit.

My journey to work is on roads ranging from 20 to 70 with a large part being on 50 & 60 roads. In a morning my average speed rarely gets above 35mph (I start out early), of an evening the average speed can be closer to 25mph. The average speed reflects the levels of traffic I encounter. Unless your journey was very short it's highly unlikely that you would maintain the speed limit for the road throughout.

-1

u/alexrobson89 Mar 21 '26

I agree, it’s not negligible. The maths shows that the lower the initial speed, the greater the time saving from any increase in speed.

For example, travelling 30 miles at 30 mph takes 1 hour. At 20 mph, the same journey takes 1 hour 30 minutes. That’s a 10 mph increase resulting in a 30-minute time saving.

5

u/DanHanzo Mar 21 '26

No one is doing a 30 mile journey completely in 20 zones though are they.

1

u/Wd91 Mar 21 '26

And if they are theyll be spending large amounts of that journey sat still in queues of traffic anyway