Forum Topic

A40 30mph Speed Limit

Does anybody know why there is a 30mph speed limit on the A40 between Greenford and the Target Roundabout? It has been there since the New Year but nobody seems to be working there, despite a sign saying repairs to central reservation (which is blatantly not true).

Ian Fergus ● 2827d46 Comments

You will all be glad to know that the A40 from Hanger Lane to vitually Polish War memorial will be 40MPH from the 9th September...

Nicolas Ozegovic ● 2791d

If the bridge is weak/in need of repairs.Faster a vehicle is travelling greater the level of kinetic energy dissipated into the bridge, ergo quicker the weakening of the bridge, possible to collapse..

Daniel Bartlett ● 2792d

Just been on the westbound A40 and someone has blacked out some of the speed limit signs around the Tesco stretch where it changes from 40 to 50 before the Greenford flyover. Anyone know why or who?

Derek Hill ● 2794d

Signs have appeared Eastbound saying that the limit will change to 40mph from 9 Sept.

Andy Hamm ● 2796d

What this thread seems to prove to me that speed limits are introduced for spurious reasons. Some people here seem to want low speed limits everywhere. What exactly would this achieve? The reason for my starting this thread was that speed limits seem to be introduced without good reason. If drivers understand a good reason for restrictions, they are happy to oblige. There is no rationale behind the current limit, especially as no work seems to be happening. If there was really a problem with the central reservation, surely something would be done about it.

Ian Fergus ● 2799d

How could a speed limit be of any help unless someone was working on the bridge?

Graham Weeks ● 2799d

So perhaps all the work going on below unseen from the road?  That said I think it would be helpful for the understanding of motorists if they put a few signs stating something like "Weak bridge - reduced speed limits in place".  I recall seeing them elsewhere.

Philip Coe ● 2799d

Graham, wouldn't that be wonderful, no speed humps. Sadly, a lot of the drivers in London either do not know the driving laws, or ignore such things as driving laws. Regular being flased from behind on the A4, A40, or even the Uzbridge Road  by black cars with tinted windows (more often than not with minicab license stickers in their back windows) when you are sticking to the speed limit and then having them overtake you dangerously without indicators is the norm.No, I would want the speed bumps to stay on Creighton Road which I think is a 20MPH zone and the speed that these drivers get up to before "crashing" over the speed bumps is quite alarming. The noise they make is indicative of an old and disfunctional suspension (car shock absorbers are designed to last for five years, springs, etc.) and makes you wonder what lies beneath the well polished/re-sprayed exterior of many of these minicabs (and cars) and how they got through their MOTs.

Mark Julian Raymond ● 2799d

It's due to the condition of the A40 bridges over the canal and Kensington Road.

Daniel Bartlett ● 2799d

If we get 20mph borough wide can we then be rid of all the speed humps?

Graham Weeks ● 2800d

The distance between Target and Greenford Roundabouts is approximately 1.5 miles.  So at 40mph the time taken is 2 minutes and 15 seconds.  At 30mph this stretches to 2 minutes and 45 seconds.Half a minute on your journey time to improve safety and to stay within the law

Philip Coe ● 2802d

'Shortly there'll be a 20mph borough wide speed limit which will be enforced.' Presumably not on the A406 or A40. Enforced? It is not at present where it exists, it is not even adequately signed. Will it apply to cyclists or be yet another law they break with impunity?

Graham Weeks ● 2802d

You can use the A40 30mph speed limit as anew opportunity to practice driving at lower speeds without making a significant impact on your journey time.Shortly there'll be a 20mph borough wide speed limit which will be enforced.

Ben Owen ● 2802d

Oops, MEGA-correction, I meant that the biggest disaster road-wise in Ealing was that the campaign to STOP the Hanger Lane and Gunnersbury Lane being pur underground succeeded, therefore, sic.,"The biggest disaster road-wise that Ealing ever had was when the campaign to STOP putting the Hanger Lane and Gunnersbury Lane underground between the A40 Hanger Lane Gyratory and the A4 succeeded. The campaign focused on saving the horsechestnut trees on Ealing Common (which a) are non-native, and b) are dying now), thankfully the fossils that spearheaded this campaign are pretty much gone now or on their way out. If you want to conserve Ealing, bypass the traffic from AROUND it."

Mark Julian Raymond ● 2803d

The biggest disaster road-wise that Ealing ever had was when the campaign to put the Hanger Lane and Gunnersbury Lane underground between the A40 Hanger Lane Gyratory and the A4 succeeded. The campaign focused on saving the horsechestnut trees on Ealing Common (which a) are non-native, and b) are dying now), thankfully the fossils that spearheaded this campaign are pretty much gone now or on their way out. If you want to conserve Ealing, bypass the traffic from it.

Mark Julian Raymond ● 2803d

The queue for the Gyratory often starts before Northolt.I noticed a mention on the tfl.gov.uk traffic status page that there is currently survey work on the central reservation between Greenford and Northolt, so perhaps something might happen in the next few years, but don't hold your breath. If something does happen it will probably involve lane restrictions.

Christopher Bell ● 2803d

accidents are usually down to driver error I read somewhere.On the approach to the Hangar Lane Gyratory there are clear markings saying A406 ONLY,same with approach to Traget Roundabout.The amount of times some ***er cuts in,queue jumps & holds up the lanes 2 & 3.Cameras should nick them

Peter Yale ● 2805d

Andy, The first part of my statement is based on the observations of a friend of mine who drives regularly up the Hanger Lane, along the A40 and then back again. Most nights there used to be some kind of incident or other during the evening rush hour and these seem not to be happening since the 30 mph came in on the A40. I wonder if anyone else has noticed the same? It might be worth graphing incidents in a 500m radius of the Hanger Lane Gyratory over time and seeing what happens after the 30 mph limit was introduced. Someone somewhere compiles a traffic incident report database, though I do not know who. Any thoughts?

Mark Julian Raymond ● 2806d

Mark, is your first sentence a statement or question? If the former, can you provide the source for your data?I agree that speed reductions can increase throughput, this is noticeable on sections of managed motorways (e.g. M25) but the speed reductions are triggered by traffic density and adjusted accordingly. The problem with the A40 is that it is a blanket reduction, so we are supposed to stick to 30mph at all times even when traffic is light. The effect is to reduce drivers' confidence in the system.

Andy Herrick ● 2806d

There seem to be fewer incidents taking place on that stretch of the A40 and in the Hanger Lane gyratory? Could it be that the low speeds are helping throughput and oviating accidents?In the first year of my Computer Science degree we did a bit of flow control in network systems using a simple road traffic simulation system over a network of interconnected roads. What this showed was as the network gets more congested lowering the speed over the congested areas increased throughput when those areas were congested.Perhaps the speed limit should be reduced to 30mpg for a mile either side of the Hanger Lane Gyratory on all the feeder roads (including the Hanger Lane) to see if the throughput increases in times of congestion and whether the incident rates go down?

Mark Julian Raymond ● 2807d

Thanks for that link Fred.I wouldn't have thought that replacing a small barrier on a mile or so of major road into London would have been a huge sum compared to some of the other projects being done.I wonder how much longer it will take for funds to appear?

Andy Hame ● 2811d

TfL have run out of money ITV says - http://www.itv.com/news/london/2018-08-16/drivers-told-to-slow-down-because-transport-chiefs-cant-afford-essential-repairs/

Fred Hunt ● 2813d

I suspect that it is an experiment by TFL to introduce a speed limit for the most spurious of reasons and see what the effect will be. I can guarantee that there will be no protest from Ealing Council.

Ian Fergus ● 2813d

The speed limit came in before Christmas 2017, and to this date I have never seen any work going on to repair the safety barrier.I don't know why the barrier is no longer safe, nor why it needs such a low speed limit.There are thousands of miles of roads in the UK at the national speed limit which have no barrier at all. The A40 with a central reservation must be safer than those surely?Is it something to do with the classification that the A40 has?

Andy Hame ● 2816d

exactly, always the motorist

Peter Yale ● 2818d

If the safety barriers are dangerous, why has there been no attempt to replace them. The limit has only been in place for eight months. Have the barriers always been unsafe? It is a bit like the Target Roundabout underpass which had the breakdown lanes closed off for a couple of years with no obvious work being done. Spurious speed limits cause the law to be disrespected unfortunately.

Ian Fergus ● 2820d

Most roads, including single carriageways with speed limits of up to 60mph do not have a central barrier. So this is not a valid reason to impose a 30mph limit.

Andy Herrick ● 2820d

Peter, it's 30mph because the central barrier has found to be unsafe.

Paul James ● 2821d

its an A road, cars speed. Who walks or plays on there?Another tax scheme.Motorists held up & penalised for no reason.Theres never been an issue except twats cutting across trying to queue jump

Peter Yale ● 2821d

Precisely my point. If you have a limit - enforce it or it has no weight at all.

Graham Weeks ● 2822d

If not enforced why have a limit? Are you being serious?

Paul James ● 2822d

Ho Ho. Driving 50 years and never had a ticket. If not enforced why have a limit?

Graham Weeks ● 2822d

I find my sat nav is a big help in observing speed limits. It sounds if I speed.

Graham Weeks ● 2822d

If the speed average cameras have been adjusted for the 30 mph limit, people will be in for a shock!Anyone got a ticket yet?

Nick Robinson ● 2822d

Never, ever trust your sat nav to tell you what the speed limit is... use the signs on the road.

Paul James ● 2822d

They only need enforcing because of law breakers like you Graham.

Paul James ● 2822d

They need enforcing for laws not enforced might as well not exist.

Graham Weeks ● 2823d

Why do limits need enforcing?It's the law not to exceed them right?

Paul James ● 2823d

If that is the case and the limit is not enforced, what is the point? It is not fit for purpose. When will work be done to replace the barrier? The limit has been there for how many months to no purpose?

Graham Weeks ● 2824d

So anybody going faster than 30mph that hits a barrier could break through it onto the opposite carriageways.Graham?

Paul James ● 2824d

There was a report that the safety barriers are only safe up to 30 MPH, so that is the limit until they are replaced.

Christopher Bell ● 2825d

I could not possible comment.

Graham Weeks ● 2826d

You don't?

Paul James ● 2827d

What I do understand that apparently pointless regulations which are not enforced bring the rule of law into disrespect. And I thought my wife was the only driver who observes the silly restriction!

Graham Weeks ● 2827d

It seems to be for unattended or over night road works, that have not been registered with Sat Nav providers so most sat navs and car speed limit warnings are showing 40 miles per hour, my car displays the current speed limit on a head up display, this system is excellent but does rely on local councils informing when a limit changes.The average speed limit actual works well on the A40, just not when it changes to 30 for no real reason,

Declan Devine ● 2827d

I traveled along there the other day at 30mph to GREAT consternation from many drivers around me.What do people not understand about the law?

Paul James ● 2827d