20mph speed limit rollout by Lewisham Council (effective September 2016)


The boys and girls in blue were out this morning with speed guns and pulling people over on my road going over the 20 mph limit.
Good to see.


Did you get nabbed on your bike? :wink:

I’d actually like enforcement of the 7.5t limit too.


Too early in the morning for my old legs to break 20 mph!


Interesting reading the ACPO (Association of Chief Police Officers) guidance on policing 20mph zones, from 2013:

The updated 2015 guidelines are basically the same:


If anyone has more recent updates from ACPO, please share.


That is why there are regular signs on the road surface and beside the road. Sat nav systems (e.g. Waze) also tell you what the speed limit is on the road.

If you are stopped by the police and claim you were not aware of the speed limit, they will probably give you a penalty notice for driving without due care and attention. But they are unlikely to give you a ticket for driving at 30 mph - it can happen but not very often.

The whole purpose of this project is not to reduce speeds to below 20mph, but to head that way rather than motorists routinely traveling at 40mph or more on minor roads.


Worth noting that not all sat navs are accurate. Mine, which is google based (Audi Connect) thinks that Dartmouth Road, for example, is still 30. Maybe it’s observed speed limit rather than actual…


I recall after Cranston Road was reduced to 20 and totally ignored by virtually everyone we later got a letter from the council proudly announcing that average speed had been reduced to 27 mph (or thereabouts). I think the average speed had gone down by 2mph!


Average speed down by 2mph. And 99% of drivers are suddenly “offenders” in a farce that demeans the term. Great success!

IMO the answer to making roads safer is to get PCSOs out on the beat, observing the spectrum of dangerous driving behaviour. Slapping 20mph signs everywhere and hoping for the best - that’s just idealism.


100% agree. A 20mph sign does nothing to people who ignore it.

There is very little speeding through 20 and 30 mph villages up here because there are both citizen and police operating. It has been mentioned that the police up here are able to do so as there are more of them and less crime, not so.


Unbelievable. This is basically a free for all to ignore the speed limit, it’s utterly ridiculous.
I agree that roads should be “self-explanatory”, but it’s just not consistently achievable, and never will be in a million years. That’s why someone decided it’s a good idea to put the limit on a sign and stick it next to the road - a concept that people understand around the globe.

The only way to educate drivers who routinely speed is through severe pain in their wallet. This does not happen, so people keep doing it. As fast as possible is the norm in London rather than the exception, bar those areas that got fifty odd short horizontal lines painted on the road. The Association of British Petrol Heads Drivers agrees with that approach (except for the lines). Sticking a 20mph sign up and saying it won’t be enforced is like kindly asking the robber to not steal anymore!

Leading by example is another way of course - and it would work wonders if more people did it. The few times I happen to drive down Brockley Rise, I meticulously stick to the 20mph limit. I always get there in the end, usually as quick, and it makes me feel much more relaxed too.


We decided that 30mph was a sensible limit in built-up areas and thus for many decades, every single driver in the UK has been taught this limit before being granted a license. There is little need to signpost 30mph areas because this is the default limit in built-up areas. The limit that all drivers are taught to abide.

For a local council to buck this, and thus have to put £1.3M worth of signs in our local area (to be ignored by nearly all) is hugely questionable. It risks making a mockery of all speed limits, not just those at 20mph.

Prosecuting any driver for travelling at 25mph is farcical, which is why I support the police’s Community Road Watch efforts, which do not impose fines on people for travelling at 25mph, but instead put a visible police presence on key streets, making all drivers think carefully about how they’re driving. Speed is just one element of safe road use.

You might find it relaxing, but I’m not sure the ambulance driver trapped in needless gridlocked traffic behind you would feel the same.


If just everyone did it then there wouldn’t be an issue, but that’s not the case.

Secondly, the world has moved on since decades ago and for at least the last 20 years it has been consensus that the preferential treatment of car traffic prevalent until the 80s is outdated and has no place in modern urban transport. Indeed, 20mph in residential areas is increasingly becoming the norm on residential streets in most countries in the western world. The fact that most streets in London are factually residential doesn’t help here and is probably the actual issue, and I can see how this is annoying to some.

In particular, there is the often-cited evidence that the chance to survive being hit by a vehicle travelling 30mph is disproportionately larger than at 20mph - so the main case is safety here.

Driving at 20mph does not cause gridlock, but constant accelerating and breaking does. Which is why for instance motorways have variable speed limits. I would also have thought that you ought to make way to an ambulance behind at the next opportunity, rather than staying ahead of it but driving faster.


Says whom?


Transport planners around the world.
Probably the evidence from most streetscape redevelopments occurring in the last 20 years on the western hemisphere. Even London is starting to grasp this.


It doesn’t cause gridlock if everyone overtakes the one driver travelling at 20mph.

But overtaking on narrow London roads is very dangerous.

This anecdote is an interesting counter-point:

The 20mph experiment is interesting from a scientific point of view. There are all sorts of side effects that emerge. If it is shown empirically to be counter-productive, we must set aside our ideology about “preferential treatment of cars” and restore 30mph limits for the public good.


So no actual motorists, more groups with an interest in making money then.

I am sure if I had the time and inclination I would be able to find academics, transport planners and streetscape developers who disagree with you but such is life.

Can I ask why a blanket 20 mph limit is a good idea when, as Chris has already said, academics, streetscape developers etc were quite happy with 30 mph limits? We also seem to have forgotten that cars themselves are safer, my bunny hugging Volvo stops automatically when any myopic iPhone users make a bold dash across the road without looking.

Once again the many are disadvantaged because of the few.


We’re not citing this stupid article again, are we? The article doesn’t mention one piece of data which doesn’t have a glaring hole in it. It probably takes some skill to take facts and obfuscate them so effectively.


Is it stupid because you dont like it and it doesnt reflect you views or something else?


No, it’s stupid because it provides near irrelevant data which have been derived from relevant, but not provided, data.


Irrelevant? The number of accidents has fallen across Manchester, but fallen less in 20 mph zones than in 30 mph zones. It’s a small dataset, but it certainly supports the arguments of those of us who warned about the negative consequences of 20 mph limits.


If you can find better data that refutes this, perhaps share it?