Roundabout fences reducing visibility

ianh · 23 Oct 2010 at 16:21

MrMatteh said:
another one in Salisbury

http://maps.google.co.uk/?ie=UTF8&h...d=wyZoj1_eQTexr4qyhRceOQ&cbp=12,251.03,,0,6.4

I was just going to post that exact same one. It used to be yellow/black metal chevrons about 8-10ft tall until 6 months ago, now it's this shorter wooden version.

Driving should be made more dangerous, rather than safer. Once Darwinism has culled the herd those drivers left alive should be quite safe

hominid · 23 Oct 2010 at 17:01

I've not seen one of these before but it must be one of the stupidest thing I've seen for 'traffic management'.

MrMatteh · 23 Oct 2010 at 18:09

They'll be reducing the speed limits soon, citing poor visibility

Smokey McPot · 23 Oct 2010 at 19:20

Be interesting to see them make their way to Milton Keynes.

squerble · 23 Oct 2010 at 22:19

There's one coming off the A49 near Wigan that really annoys me. Stupid black and white arrows; completely blocks the view of the traffic coming off the motorway.

http://maps.google.co.uk/?ie=UTF8&l...=YdbYbT-M-nffRmIPy42MlA&cbp=12,191.56,,0,9.71
(Motorway from right/2 oclock on the link)

Scania · 23 Oct 2010 at 22:23

I have noticed this recently too - I was on that very M5/M50 roundabout this afternoon!

I see the logic, but think its a daft idea.

Thankfully, I have a height advantage in an HGV and can (just) see whats coming.

I'll end up with a Smart under me one day though - those things need warning flags !

Uriel · 23 Oct 2010 at 22:30

Hate them. Nearest ones to me are these (Google caught them being constructed). http://maps.google.co.uk/maps?f=q&s...YgsnS4TZ3XaB7usV5QqT4A&cbp=12,245.18,,0,11.08

ridiculous design. Roundabout had great visibility. Even if I agreed that it would be remotely helpful to reduce visibility, why not plant a hedge or something less ugly?

ChrisJSY · 24 Oct 2010 at 04:38

What are the chances people will drive straight over because they are that stupid?

Scania · 24 Oct 2010 at 04:41

ChrisJSY said:
What are the chances people will drive straight over because they are that stupid?

From the number of tyre tracks I see running onto roundabouts, I'd say pretty high.

Alas, a lot of our road users are not drivers, not by a long shot.

snowdog · 24 Oct 2010 at 05:40

Christ that is shocking. Still, you're all still that they don't plant traffic lights instead like they do on any major ( and I use that term very loosely, anything with more than 2 lanes) roundabout around here. But those roundabouts looks fine as they were without the fences !

Fusion · 24 Oct 2010 at 14:25

One that I had in mind was when coming south from Chesterfield on the A617 to J29 of the M1- it's a grey metal barrier with no way of seeing through it. Well stupid. That fence with the foliage planted in made me laugh, what a ridiculous creation!

Duke · 24 Oct 2010 at 15:29

Wow, not seem them before but they look a complete waste of time and money.

SoliD · 24 Oct 2010 at 16:57

Noticed this ever increasing near here too, couple up by waterlooville, very frustrating, slows the traffic down, no safety improvements, just makes things worse I would say.

http://maps.google.co.uk/maps?f=q&s...=4VnLrAOYveFMBM1NsB60Qg&cbp=12,150.8,,0,-6.31

MikeHunt79 · 24 Oct 2010 at 18:37

Duke said:
Wow, not seem them before but they look a complete waste of time and money.

I agree, so much for cutting back during the recession...

Tourm · 25 Oct 2010 at 11:38

Only just noticed this topic.

The official answer from the Design Manual For Roads And Bridges (DMRB) - Geometric Design of Roundabouts:

8.8 Excessive visibility to the right can result in high entry speeds, potentially leading to accidents. On dual carriageway approaches where the speed limit is greater than 40mph, limiting visibility to the right by screening until the vehicle is within 15 metres of the give way line can be helpful in reducing excessive approach speeds.

The screening should be at least 2m high, in order to block the view of all road users. Screening can also be used on flared approaches on high speed single-carriageway roads where there is a long splitter island.

From my experience its a last resort.
Newer roundabouts should have this problem designed out (increased entry path radius) although older, existing ones with a history of accidents due to excessive speed have them because it's cheaper than reworking the approach where - minus the issue of speed, the roundabout works fine.

Uriel · 25 Oct 2010 at 12:09

I note "in order to block the view of all road users".

Ironically every fence I've seen has been no more than about 2m high, meaning that only the drivers of vehicles with the greatest momentum, who are least likely to be able to stop if they are travelling too fast, are unrestricted. Genius...

Clearly following the letter, rather than the spirit, of the guidelines.

DRZ · 25 Oct 2010 at 12:26

Tourm said:
Only just noticed this topic.

The official answer from the Design Manual For Roads And Bridges (DMRB) - Geometric Design of Roundabouts:

Yeah.

Could have sworn someone has already posted this in the thread though?

XeNoN89 · 25 Oct 2010 at 13:21

I have seen these even at traffic light controlled roundabouts, which is pointless surely?

Like here: http://maps.google.co.uk/maps?hl=en...=7kKZ99A99DOnmAOwhJDciw&cbp=12,182.06,,0,9.92

Uriel · 25 Oct 2010 at 13:29

XeNoN89 said:
I have seen these even at traffic light controlled roundabouts, which is pointless surely?

Like here: http://maps.google.co.uk/maps?hl=en...=7kKZ99A99DOnmAOwhJDciw&cbp=12,182.06,,0,9.92

That fence looks less than 2m - so isn't regulation compliant. I'm guessing they put the fence in first, then added the lights.

XeNoN89 · 25 Oct 2010 at 13:31

Uriel said:
That fence looks less than 2m - so isn't regulation compliant. I'm guessing they put the fence in first, then added the lights.

Nah the lights have been there for as long as i can remember, fence was added after. I have no idea why