Ask a highways designer/engineer anything, anything at all..
Discussion
Been threatening this one for a while now, and a fair number of people have said it could be quite interesting (and GG-related), so thought I'd actually do something about it...
I am a Chartered Engineer, based in highways my whole career. Ten years on HA stuff, and another ten or so on smaller stuff, from local roads to army bases (tanks and helicopters need beefy, track-proof roads...) to cycle infrastructure to bridges... you get the idea. Whilst not "on the tools" per se, I've done everything from initial surveys, environmental works, design, supervision of construction, pretty much all elements of the job. I've worked in Ireland, America and India doing similar things. Have also helped the odd PH-er with local roads-based problems, queries and, er, feedback on what's REALLY s
t...
So, if anyone has any queries about what's going on near them, why certain layouts or arrangements have been chosen, why speed limits may be lowered - or raised - or any other highways-based question, then I will try to give you an answer or insight. There are a few of us on here, so obviously if they want to help answer some questions or give the benefit of their knowledge, feel free. I will answer as and when I can, probably mostly early morning and late evening.
All answers will be my opinion, unless I know specifics about the scheme. I am not a spokesman for the local authorities policy dept, nor am I in any way political, so that type of question will be answered in a very broad, high-level way.
So... Ask away!
I am a Chartered Engineer, based in highways my whole career. Ten years on HA stuff, and another ten or so on smaller stuff, from local roads to army bases (tanks and helicopters need beefy, track-proof roads...) to cycle infrastructure to bridges... you get the idea. Whilst not "on the tools" per se, I've done everything from initial surveys, environmental works, design, supervision of construction, pretty much all elements of the job. I've worked in Ireland, America and India doing similar things. Have also helped the odd PH-er with local roads-based problems, queries and, er, feedback on what's REALLY s
t...So, if anyone has any queries about what's going on near them, why certain layouts or arrangements have been chosen, why speed limits may be lowered - or raised - or any other highways-based question, then I will try to give you an answer or insight. There are a few of us on here, so obviously if they want to help answer some questions or give the benefit of their knowledge, feel free. I will answer as and when I can, probably mostly early morning and late evening.
All answers will be my opinion, unless I know specifics about the scheme. I am not a spokesman for the local authorities policy dept, nor am I in any way political, so that type of question will be answered in a very broad, high-level way.
So... Ask away!
Ninja59 said:
What is the most frustrating bit of highways design?
Why do some high speed sections have very sharp cambers? (A500 comes to mind in some sections)
Also who dreamt up the "hamburger" roundabout?
Most frustrating bit is probably when you finish a road scheme, and then 3 weeks later BT come in and cut a trench through, stain the nice new blacktop, break some drainage, over-run their programme, and then reinstate badly. People just see "roadworks" and assume it's us. Why do some high speed sections have very sharp cambers? (A500 comes to mind in some sections)
Also who dreamt up the "hamburger" roundabout?
High speed section camber, or superelevation, is a design measure to increase speed through an otherwise tight corner - the more superelevation you have, the less stopping sight distance you need - i.e. you can have a tighter bend. Not too dissimilar from Scalextric!
The hamburger roundabout is a relatively recent development. It does work, there are a few near me that I know and they work OK - they do need signals and they are best used on larger, busier roundabouts, IMO. I don't know who first came up with the idea...
Figured i'd ask a question that i ponder every day on the way home.
On the A127 there is a bottleneck called ''the fortune of war'' which creates congestion from j29 of the m25 at rush hour, I know historically it used to be problematic for trucks and lorrys so they changed the layout a bit and added speed cameras to try and slow them down and stop them toppling over but i can't help but feel as i drive past a better solution must exist. Just wondered what your thoughts on how it currently stands and if anything could possibly be done to alleviate it.
I did see an article around Christmas time that said they were rumors of a congestion charge on the road due to the air pollution and excess emissions, which this bottleneck must play a rather large part in as every car slows to 20-40 before going right back up to 70-80 so i do hold out some chance that it may get looked at eventually.
On the A127 there is a bottleneck called ''the fortune of war'' which creates congestion from j29 of the m25 at rush hour, I know historically it used to be problematic for trucks and lorrys so they changed the layout a bit and added speed cameras to try and slow them down and stop them toppling over but i can't help but feel as i drive past a better solution must exist. Just wondered what your thoughts on how it currently stands and if anything could possibly be done to alleviate it.
I did see an article around Christmas time that said they were rumors of a congestion charge on the road due to the air pollution and excess emissions, which this bottleneck must play a rather large part in as every car slows to 20-40 before going right back up to 70-80 so i do hold out some chance that it may get looked at eventually.
Dark85 said:
Part-time working traffic lights,mostly on roundabouts, seem to be becoming much less common, have they fallen out of favour and if so, why?
That's a planning/modelling question really - but in my experience, roundabouts are either big enough that they work without signals (they may have dedicated left turn lanes or other physical measures to increase the footprint/capacity) or they are designed with full-time signals from the start. I have put in part-time signals recently (M25 J9a for example). How high would you have to be to design something like this?
https://www.google.co.uk/maps/@55.6298965,-4.64468...
https://www.google.co.uk/maps/@55.6298965,-4.64468...
Great thread. Thanks. 
Ever hear interesting anecdotes from old timers who, say, worked the initial stages of the M25?
Within the next 10 years, what are we likely to see (anywhere in the world) in actual use in terms of embedded solutions?
Name a couple of methods / solutions / achievements which were generally hatched outside the UK -- which, when you first saw them, you thought, "Crikey, that's not too bad an idea."
Ever hear interesting anecdotes from old timers who, say, worked the initial stages of the M25?
Within the next 10 years, what are we likely to see (anywhere in the world) in actual use in terms of embedded solutions?
Name a couple of methods / solutions / achievements which were generally hatched outside the UK -- which, when you first saw them, you thought, "Crikey, that's not too bad an idea."
Who is it that actually decides to replace perfectly functional traffic light free junctions and roundabouts with light controlled junctions and roundabouts that create gigantic queues and congestion where previously there were none? It seems to be a never ending quest, more and more all the time and they invariably make things worse but somebody somewhere must think it's a great idea?
Do you feel that development in cities in the last 10-15 years has had a detrimental effect on traffic flow (bus lanes, bus gates, pedestrianisation, one way systems etc etc), or is it one of those 'all in your head' or more related to the ever increasing volume of traffic?
I assume some are worse than others, for me personally I remember Glasgow being a doddle to navigate, the whole city was a grid. However more recently with the one way system about 10 years ago, and the bus gates that have been put in in the last 5 years it's turned the city, in my opinion, into a genuine nightmare to drive through.
I assume some are worse than others, for me personally I remember Glasgow being a doddle to navigate, the whole city was a grid. However more recently with the one way system about 10 years ago, and the bus gates that have been put in in the last 5 years it's turned the city, in my opinion, into a genuine nightmare to drive through.
OpulentBob said:
RizzoTheRat said:
Who's responsible for the layout of the painted markings on roundabouts and junctions,
The design engineers. RizzoTheRat said:
and do the people who do it in Hampshire have driving licences?
Is it a single design department though the life of the road or does it get designed by one agency and then handed over to a local one to maintain it?
I can think of a few roundabouts near me that got repainted several times with new layouts over the course of a couple of years, so presumably it's an on-going process involving monitoring traffic flow?
457892345 said:
Figured i'd ask a question that i ponder every day on the way home.
On the A127 there is a bottleneck called ''the fortune of war'' which creates congestion from j29 of the m25 at rush hour, I know historically it used to be problematic for trucks and lorrys so they changed the layout a bit and added speed cameras to try and slow them down and stop them toppling over but i can't help but feel as i drive past a better solution must exist. Just wondered what your thoughts on how it currently stands and if anything could possibly be done to alleviate it.
I did see an article around Christmas time that said they were rumors of a congestion charge on the road due to the air pollution and excess emissions, which this bottleneck must play a rather large part in as every car slows to 20-40 before going right back up to 70-80 so i do hold out some chance that it may get looked at eventually.
I know it well, very well indeed.On the A127 there is a bottleneck called ''the fortune of war'' which creates congestion from j29 of the m25 at rush hour, I know historically it used to be problematic for trucks and lorrys so they changed the layout a bit and added speed cameras to try and slow them down and stop them toppling over but i can't help but feel as i drive past a better solution must exist. Just wondered what your thoughts on how it currently stands and if anything could possibly be done to alleviate it.
I did see an article around Christmas time that said they were rumors of a congestion charge on the road due to the air pollution and excess emissions, which this bottleneck must play a rather large part in as every car slows to 20-40 before going right back up to 70-80 so i do hold out some chance that it may get looked at eventually.
Yes it used to be a roundabout. For some reason, back in the early 90's (I was still at school) it was "cut off" so that the circulatory remains but you can't do a loop. Speed cameras are there to stop trucks overturning, as you say.
Map for those interested: https://goo.gl/maps/wh3shGJVCHA2
There are issues with straightening the road. Increasing the speed limit would mean that new slips would need to be installed to the north and the south. These would be very long (in the order of 500m) at 50mph+, therefore the McDonalds, the Esso, the footbridge, road bridge and a load of flats to the north-east would need to be demolished (megabucks in compo), and new bridges would need to be installed to allow vehicles and pedestrians to cross the A127. This would probably all come to £10million, at a rough guess.
The land through there is utter s
te, contaminated and filthy. To dig a bridge foundation would need a huge amount of licensed waste, unexploded ordnance surveys (and probably removal), not to mention the road would need to be closed for probably months. BT, for example, want the road closed and sole possession for 18 months, and £3million+, just to do their diversions - not to improve, just to move their current old ducting out of the way. Then add similar for gas, for UKPN, comms etc and it becomes unfeasible. It's better for all to just leave it alone!
Whoever came up with the traffic light flow/system/sequence here deserves a medal: click.
This is a busy junction at peak times and was a notorious local black-spot with several serious accidents every year. When the lights were first installed we all feared the worse, assuming flow would be buggered.
It's brilliant. Still get queues when it's really busy, but that's because it's busy.
Everyone knows the sequence. Better than that, when it's quiet and it's just the odd car every five minutes the main route is green and doesn't change until someone approaches from one of the other directions - it changes promptly.
Quite the finest set of lights in the whole world ever.
Quite why the rest of them around here are so irritatingly dumb I have no idea. Clearly, it can be done properly - but the ring-road in particular with its plethora of roundabouts with lights is just irksome and causes chaos 24/7.
This is a busy junction at peak times and was a notorious local black-spot with several serious accidents every year. When the lights were first installed we all feared the worse, assuming flow would be buggered.
It's brilliant. Still get queues when it's really busy, but that's because it's busy.
Everyone knows the sequence. Better than that, when it's quiet and it's just the odd car every five minutes the main route is green and doesn't change until someone approaches from one of the other directions - it changes promptly.
Quite the finest set of lights in the whole world ever.
Quite why the rest of them around here are so irritatingly dumb I have no idea. Clearly, it can be done properly - but the ring-road in particular with its plethora of roundabouts with lights is just irksome and causes chaos 24/7.
Silverbullet767 said:
How high would you have to be to design something like this?
https://www.google.co.uk/maps/@55.6298965,-4.64468...
Scotland, innit. I haven't got a clue, I'm only concerned about REAL roads. https://www.google.co.uk/maps/@55.6298965,-4.64468...
How much research / local knowledge goes into planning alterations to the roads?
For example there is a crossroads near me that has been a total nightmare for years. Its traffic light controlled but the lights are set up on a bad cycle so you end up with massive tailbacks at peak times. This leads to loads of impatient people running the red lights and nearly coming together.
We have just gotten over a months worth of hell while they installed pedestrian crossings into the mix too. (it was supposed to take 7 days). This was done in response to someone I went to school with getting squashed under a lorry, though how the pedestrian bit helps I don't know as she was blown off the pavement by wind and was not crossing at the time.
The problem is the cycle of the lights is still the same which means massive tailbacks and red light jumpers. Now added into that mix is the pedestrian crossing, that when requested gives a green man to all 4 crossing points at the end of the cycle. So now we have impatient people jumping red lights and pedestrians thinking its safe to cross at the same time!
What really needs doing is the cycle of the lights changing and it will massively reduce the traffic and pissed off drivers.
For example there is a crossroads near me that has been a total nightmare for years. Its traffic light controlled but the lights are set up on a bad cycle so you end up with massive tailbacks at peak times. This leads to loads of impatient people running the red lights and nearly coming together.
We have just gotten over a months worth of hell while they installed pedestrian crossings into the mix too. (it was supposed to take 7 days). This was done in response to someone I went to school with getting squashed under a lorry, though how the pedestrian bit helps I don't know as she was blown off the pavement by wind and was not crossing at the time.
The problem is the cycle of the lights is still the same which means massive tailbacks and red light jumpers. Now added into that mix is the pedestrian crossing, that when requested gives a green man to all 4 crossing points at the end of the cycle. So now we have impatient people jumping red lights and pedestrians thinking its safe to cross at the same time!
What really needs doing is the cycle of the lights changing and it will massively reduce the traffic and pissed off drivers.
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