Why do they deliberately obscure vision at roundabouts?
Discussion
Censorious said:
OpulentBob said:
Paragraph 8.8
http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
A diabolical idea if it is only applied to one exit at a roundabout.http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
The effect is bringing 2 cars together to emerge but at very different speeds, one with no idea that the other is approaching quite fast to emerge at speed whilst they are trying to set off from a standstill.
An accident waiting to happen!
sorry)A roundabout entry is a give way situation. So give way, and wait for a gap... [/vonhosen]
OpulentBob said:
HertsBiker said:
Bob, interesting stuff you write. Tell us more of this bus company.. I see buses as a rolling road block anyway, and this latest tactic of theirs really suck!
Pick a bus company! One typical one rhymes with WageRoach. I've worked in 4 different counties and the bus companies generally are all the same. They will look for any minor infrastructure criticism to blame for running late/rising costs/reducing services. Near me, a 20mph limit is coming in. Bus companies are objecting as they say it will slow them down. Their average speed as surveyed? 19mph. And they're threatening withdrawal of service. Go figure. It's rather
It really is stupid to reduce visibility. The other consequence being people turning right cannot see if the exit from the roundabout is clear before joining it. The result being roundabouts even more clogged up with cars stuck on them without a clear exit and blocking the other junctions with clear exits causing unnecessary congestion.
RenesisEvo said:
Ah yes - traffic lights on roundabouts. If ever there was something more pointless I'm not aware of it.
Pretty certain then.RenesisEvo said:
Admittedly there are cases where part-time lights do have a benefit, when the traffic is such that everyone is hardly moving.
Oh hang on. They DO have a benefit? Make your mind up.Do you not think that years of research, modelling and design might possibly have some benefits, and have some grounding in fact? Or, should we leave it all to armchair experts and DM/PH readers, and scrap the TRL? Are you actually aware of the HUGE increase in vehicle ownership and traffic figures over the last 20-40 years, and the impact it has on the road network?
OpulentBob said:
HertsBiker said:
Bob, interesting stuff you write. Tell us more of this bus company.. I see buses as a rolling road block anyway, and this latest tactic of theirs really suck!
Pick a bus company! One typical one rhymes with WageRoach. I've worked in 4 different counties and the bus companies generally are all the same. They will look for any minor infrastructure criticism to blame for running late/rising costs/reducing services. Near me, a 20mph limit is coming in. Bus companies are objecting as they say it will slow them down. Their average speed as surveyed? 19mph. And they're threatening withdrawal of service. Go figure. It's rather
Truffles said:
OpulentBob said:
HertsBiker said:
Bob, interesting stuff you write. Tell us more of this bus company.. I see buses as a rolling road block anyway, and this latest tactic of theirs really suck!
Pick a bus company! One typical one rhymes with WageRoach. I've worked in 4 different counties and the bus companies generally are all the same. They will look for any minor infrastructure criticism to blame for running late/rising costs/reducing services. Near me, a 20mph limit is coming in. Bus companies are objecting as they say it will slow them down. Their average speed as surveyed? 19mph. And they're threatening withdrawal of service. Go figure. It's rather
OpulentBob said:
Censorious said:
OpulentBob said:
Paragraph 8.8
http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
A diabolical idea if it is only applied to one exit at a roundabout.http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
The effect is bringing 2 cars together to emerge but at very different speeds, one with no idea that the other is approaching quite fast to emerge at speed whilst they are trying to set off from a standstill.
An accident waiting to happen!
sorry)A roundabout entry is a give way situation. So give way, and wait for a gap... [/vonhosen]
I know of one roundabout where you'll easily sit for 5-10 minutes waiting for a gap as the traffic to the right has a fantastic view of all it's exit points.
You'll go to emerge several times to then have to brake as a car doing 30+ becomes visible from behind the bank and bushes to your right.
You can "creep & peep" to get a better view but this particular roundabout has such a poor view on that exit that you'd be fully emerged by the time you can see traffic approaching to the right.
Truffles said:
OpulentBob said:
Not average speed of 19mph across the whole bus route. An average of 19mph at 4 individual point locations along the route. (18.9, 18.7, 19.1, 19.4mph)
Well, it depends on whether those are the fastest parts of the route or not. Censorious said:
OpulentBob said:
Censorious said:
OpulentBob said:
Paragraph 8.8
http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
A diabolical idea if it is only applied to one exit at a roundabout.http://www.dft.gov.uk/ha/standards/dmrb/vol6/secti...
"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."
The effect is bringing 2 cars together to emerge but at very different speeds, one with no idea that the other is approaching quite fast to emerge at speed whilst they are trying to set off from a standstill.
An accident waiting to happen!
sorry)A roundabout entry is a give way situation. So give way, and wait for a gap... [/vonhosen]
I know of one roundabout where you'll easily sit for 5-10 minutes waiting for a gap as the traffic to the right has a fantastic view of all it's exit points.
You'll go to emerge several times to then have to brake as a car doing 30+ becomes visible from behind the bank and bushes to your right.
You can "creep & peep" to get a better view but this particular roundabout has such a poor view on that exit that you'd be fully emerged by the time you can see traffic approaching to the right.
OpulentBob said:
Truffles said:
OpulentBob said:
Not average speed of 19mph across the whole bus route. An average of 19mph at 4 individual point locations along the route. (18.9, 18.7, 19.1, 19.4mph)
Well, it depends on whether those are the fastest parts of the route or not. 
Centurion07 said:
OpulentBob said:
Truffles said:
OpulentBob said:
Not average speed of 19mph across the whole bus route. An average of 19mph at 4 individual point locations along the route. (18.9, 18.7, 19.1, 19.4mph)
Well, it depends on whether those are the fastest parts of the route or not. ETA average speeds have to be around 24mph or less to be considered properly suitable for a 20mph limit. If a road has an average of 30mph, then there must be good supporting reasons for a reduction.
Edited by OpulentBob on Thursday 17th April 10:35
OpulentBob said:
Can you give us a streetview link? I'm genuinely interested - bad design should be criticised as much as good design should be aplauded.
I can't grab an image and annotate it but let's see if this works as a link:-https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
It's the road to the right of the image.
You can't get an idea of the restricted view from this or street map but it's quite poor.
It'd be OK if the traffic was all approaching at the same speed but as you can see, the traffic heading to Blean has a great view and an almost straight run across the roundabout hence an enormous speed differential to those trying to join.
Edited by Censorious on Thursday 17th April 10:42
Censorious said:
I can't grab an image and annotate it but let's see if this works as a link:-
https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
Do you mean the exit from the westbound A299? To be honest that looks like a good site for part-time signals. It's a horrible entry angle to the roundabout, considering the amount of traffic that presumably comes across the top of the junction.https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
ETA never mind, seen your edit. Yep I agree. Not ideal...
OpulentBob said:
Censorious said:
I can't grab an image and annotate it but let's see if this works as a link:-
https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
Do you mean the exit from the westbound A299? To be honest that looks like a good site for part-time signals. It's a horrible entry angle to the roundabout, considering the amount of traffic that presumably comes across the top of the junction.https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
Emerging there is like running the gauntlet as there are 2 lanes of traffic approaching to your right.
Those turning to their right to join the sliproad onto the A299 are not so much of an issue as they have to go slower to take their 3rd exit. It's the traffic going straight across that is an issue as it's a straight run across with all the benefit of good visibility of the exit they are taking.
Cars doing 30 straight across often BLAST at those emerging but what do those cars do, stop across the traffic and block half the roundabout or carry on and hope the car doing 30 brakes.
I usually look as long as is sensible and then move off quickly and if someone appears, floor it as hard as possible.
This morning I got dangerously close to someone who had already passed from my right turning right but I was trying to get out of the way of the approaching car.
Part-time signals would be an excellent solution!
Some of the recent road planning locally to me has been quite good and solved issues, but some of it beggars belief and has created a problem far worse than the one it tried to cure, nobody is right all the time including road planners but when things are clearly wrong the changes stay, that's the annoying bit for me.
Speed bumps are the devils tool, many round here cannot be taken at more than 15 mph on a road with a 30 limit which is stupid, designing a road where if you drive at the speed limit you'd potentially damage your car is not good road planning. There is one piece of semi rural b road, a 20mph zone (no schools/shops/hospitals/kitten factory on or near the road) where you have to take them at 5-10mph, it's bonkers.
People I know have changed cars to SUVs because of the local speed hump policy, so we now have more large and heavy cars as a response to local road planning, talk about unintended consequences.
Censorious said:
OpulentBob said:
Censorious said:
I can't grab an image and annotate it but let's see if this works as a link:-
https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
Do you mean the exit from the westbound A299? To be honest that looks like a good site for part-time signals. It's a horrible entry angle to the roundabout, considering the amount of traffic that presumably comes across the top of the junction.https://www.google.co.uk/mapmaker?ll=51.339718,1.0...
Emerging there is like running the gauntlet as there are 2 lanes of traffic approaching to your right.
Those turning to their right to join the sliproad onto the A299 are not so much of an issue as they have to go slower to take their 3rd exit. It's the traffic going straight across that is an issue as it's a straight run across with all the benefit of good visibility of the exit they are taking.
Cars doing 30 straight across often BLAST at those emerging but what do those cars do, stop across the traffic and block half the roundabout or carry on and hope the car doing 30 brakes.
I usually look as long as is sensible and then move off quickly and if someone appears, floor it as hard as possible.
This morning I got dangerously close to someone who had already passed from my right turning right but I was trying to get out of the way of the approaching car.
Part-time signals would be an excellent solution!
http://goo.gl/maps/UPmqX
OpulentBob said:
Whilst a larger scale, this link shows a very similar situation - vehicles travelling round the roundabout at 40+mph mean traffic exiting the M25 used to have a nightmare. Part time signals have sorted it. There are a few criteria that would need to be met - queuing and stacking space, and enough space to get detectors and controllers in, but it looks like a prime candidate. Especially if waiting traffic extends to the main line A299. Maybe worth an email to whoever gets in at the next local election...
http://goo.gl/maps/UPmqX
But it's an absolutely terrible idea simply because the average PH director type might want to steam through the roundabout at 3am on Tuesday unfettered by those pesky, pointless traffic lights. http://goo.gl/maps/UPmqX
braddo said:
But it's an absolutely terrible idea simply because the average PH director type might want to steam through the roundabout at 3am on Tuesday unfettered by those pesky, pointless traffic lights.
That's fine. Anyone with a PH smily gets a remote control clicker which automatically switched the lights to green on approach. 
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