'A40 speed limit: is TFL incompetent or misleading? ' blog discussion

Lum

There are many speed limits lowered for spurious reasons, though the most common one I'm seeing these days is where a road was formerly NSL and 99% of the road is perfectly good for it, but it may have one or two sharp corners.

Previously the practice was that such corners would get a warning sign with an advisory maximum speed and this was fine.

Then one day some idiot teenager who was speeding anyway comes off on the corner and gets killed. Of course the parents refuse to believe that their son was driving like a nob and demand that something must be done about this dangerous high-speed road with sharp corners, even though thousands of drivers go around the corner every day without incident.

In order to be seen doing something the limit on the whole stretch gets dropped to 40.

This becomes dangerous when someone driving down the road who isn't totally familiar with the area is driving down that road, at 40, being overtaken by everybody. Eventually they come to the conclusion that this 40 limit is, in fact, bobbins as the road is clearly good for more and so chooses to ignore it.

All the people who overtook him earlier are local and know about the corner but this person just sees the thirty sign and shrugs it off as more bloody nannying and then they come a cropper too.

For really long roads with unnecessarily low limits you also have the negative safety effects of boredom, tiredness and distraction which is a wholly separate essay.

Pembroke

Well I can remember the days when the elevated section that Martin is talking about was clasified as a motorway (A40M) with all the restrictions that entails and the speed limit was at least 60 for the full length of the elevated section from White City to the Edgeware Road.

Martin, about all you (or a minion ) can do is track down the Traffic Restriction Order that must have been put in place before the works were started and see what it says. The standard format (at least here is West Wales) is to say blah, blah speed limit from point A to point B for a set time (can be a couple of years) or until the works are completed. You may need to remind TFL about the provisions of the TRO as if the one for the road works are no longer valid have the works finished for instance? and they are sticking fines on people for speeding then none of them will be valid.

I guess TFL would have the TRO although it may be Hammersmith & Fulham or Even the Highways agency.