Reconstructing roads in the Fens

[roadtester]

I’ve mentioned here a few times a phenomenon associated with roads in the Fens - uneven settlement/drying caused by local ground conditions, which causes often severe undulations and other problems.

Visitors to the area are often deceived by local back roads that look temptingly straight, wide and traffic-free, but which will throw you into a ditch or worse if you attempt to tackle them at high speed.

Anyway, Cambridgeshire and Peterborough currently have a programme of reconstruction in which they are tackling some of the worst bits of some of the more heavily trafficked routes, which is described here:

https://www.cambridgeshire.gov.uk/resid ... =hootsuite

[Ruperts Trooper]

Are they using any new building techniques to keep the road surface more stable?

Visitors driving in the Fens at night may not realise, or forget, there's usually a "drain*" alongside so an ever-present risk of immersion if the car leaves the road.

* drain can be anything from a few feet wide to a diverted river

[roadtester]

Are they using any new building techniques to keep the road surface more stable?

Visitors driving in the Fens at night may not realise, or forget, there's usually a "drain*" alongside so an ever-present risk of immersion if the car leaves the road.

* drain can be anything from a few feet wide to a diverted river

Yes - and often it’s not possible to have barriers to prevent this happening, again because of the unstable ground conditions.

Sometimes telegraph poles alongside the road are affected by this settlement and end up leaning over at crazy angles as well. It really is unlike anything that happens anywhere else in the country as far as I know (cue a torrent of examples with photographic evidence from all over the U.K.).

I don’t know much about the construction side but I thought it was interesting that they said the newly rebuilt roads would be lighter and this would lessen the problem.

I know that in the case of the new A142 Ely bypass there are very deep piles - I assumed that was to deal with this problem, but I’m not sure.

[Bryn666]

I’ve mentioned here a few times a phenomenon associated with roads in the Fens - uneven settlement/drying caused by local ground conditions, which causes often severe undulations and other problems.

Visitors to the area are often deceived by local back roads that look temptingly straight, wide and traffic-free, but which will throw you into a ditch or worse if you attempt to tackle them at high speed.

Anyway, Cambridgeshire and Peterborough currently have a programme of reconstruction in which they are tackling some of the worst bits of some of the more heavily trafficked routes, which is described here:

https://www.cambridgeshire.gov.uk/resid ... =hootsuite

My three year old absolutely loved the bumpiness of these roads, but you're right - drive along some at more than 25 mph and you're going to either launch into a ditch or ruin your car. The ones between Boston and Skegness are really suffering from settlement.

[roadtester]

Well I can certainly see the appeal of a free roller-coaster ride!

That said, the fun aspect does wear off a bit when you have to use these roads every day.

The case I always worry about is two cars approaching from opposite directions closing on each other at high speed, with one or both being deflected into the other side of the road, causing a nasty head-on. That’s probably worse than the onto the ditch option.

[rhyds]

Silly question, but do roads authorities/repairers use a different mix/grade of surfacing on roads prone to settlement? I ask because during my holidays to Ireland there were many roads that were suffering from tar melting and the road surface becoming extremely soft during the summer (30 degrees plus air temps).

This also affected the A543 over the Denbigh moors which had to be closed, so I was assuming that as both kinds of roads traverse boggy/unstable ground that the surface mix was made more flexible to survive land shift/winter but struggled with the heat of summer.

[trickstat]

Apparently the most direct route between Peterborough and Whittlesey is one of these types of roads. I have colleagues who would probably only ever consider using it if there was a major problem with the less direct option.

[roadtester]

Silly question, but do roads authorities/repairers use a different mix/grade of surfacing on roads prone to settlement? I ask because during my holidays to Ireland there were many roads that were suffering from tar melting and the road surface becoming extremely soft during the summer (30 degrees plus air temps).

This also affected the A543 over the Denbigh moors which had to be closed, so I was assuming that as both kinds of roads traverse boggy/unstable ground that the surface mix was made more flexible to survive land shift/winter but struggled with the heat of summer.

I don’t really know, but it certainly sounds plausible - the undulations are usually associated with a lot of cracking.

[roadtester]

Apparently the most direct route between Peterborough and Whittlesey is one of these types of roads. I have colleagues who would probably only ever consider using it if there was a major problem with the less direct option.

That one’s terrible (although it’s a pleasant route in other respects).

The other cut-across between Chatteris and Peterborough runs alongside Forty Front Bank - also undulating with the additional risk of ending up in the drink if you get it wrong!

There’s no barrier but it is SPECS controlled.

[Berk]

Apparently the most direct route between Peterborough and Whittlesey is one of these types of roads. I have colleagues who would probably only ever consider using it if there was a major problem with the less direct option.

How’s about the King’s Dyke Crossing on the A605?? That’s the main reason people drive on the North Bank, and the fact it’s a lot closer to the centre of town.

But there were problems a few years back - just the usual, kids not looking out for the speed limit, approaching a bend too sharp on a winter’s night. But because the girl perished the limit was cut to 40.

[Berk]

I’ve mentioned here a few times a phenomenon associated with roads in the Fens - uneven settlement/drying caused by local ground conditions, which causes often severe undulations and other problems.

Visitors to the area are often deceived by local back roads that look temptingly straight, wide and traffic-free, but which will throw you into a ditch or worse if you attempt to tackle them at high speed.

Anyway, Cambridgeshire and Peterborough currently have a programme of reconstruction in which they are tackling some of the worst bits of some of the more heavily trafficked routes, which is described here:

https://www.cambridgeshire.gov.uk/resid ... =hootsuite

My three year old absolutely loved the bumpiness of these roads, but you're right - drive along some at more than 25 mph and you're going to either launch into a ditch or ruin your car. The ones between Boston and Skegness are really suffering from settlement.

And many more, but there just don’t seem to be the funds to fix them.

Even the ones that have supposedly been “fixed”, as well as others that aren’t showing signs of cracking do seem to be showing additional camber. The B1443 up to Thorney isn’t great to drive on at 50 (40 in some places). And the B1162, and the old A15 Lincoln Road both have a pronounced camber than was ever there before. You can definitely feel it when you pull out, or overtake.

[Reading]

Sometimes telegraph poles alongside the road are affected by this settlement and end up leaning over at crazy angles as well. It really is unlike anything that happens anywhere else in the country as far as I know (cue a torrent of examples with photographic evidence from all over the U.K.).

Here is one in Berkshire - between 2 gravel pits (hence the subsidence), looks nice and straight and smooth but there are ripples of about 6-8' duration just after the entrance to the Tarmac site which once had me totally out of the seat of my bike when i hit them at the wrong speed and the front suspension couldn't rebound before hitting the next rise.

If you zoom out and head north across the water (submerged gravel pit) the Henley Rd has just had piles and metal sheeting driven in and a complete new southern verge/embankment built to stop it sliding down the hill

[XC70]

We are a bit further north here in Scunthorpe, but the M181 suffers from what you describe with ridges forming which then have to be scalped and resurfaced. There are also some roads around the back of Epworth (basically south of the M180 between J1 and J2) which suffer in exactly the way you describe. Way back when in a company car great fun, but can imagine lethal on a motorbike.....

[Big L]

Here is one in Berkshire - between 2 gravel pits (hence the subsidence), looks nice and straight and smooth but there are ripples of about 6-8' duration just after the entrance to the Tarmac site which once had me totally out of the seat of my bike when i hit them at the wrong speed and the front suspension couldn't rebound before hitting the next rise.

If you zoom out and head north across the water (submerged gravel pit) the Henley Rd has just had piles and metal sheeting driven in and a complete new southern verge/embankment built to stop it sliding down the hill

Maybe helpful to give us a link?

[Reading]

Here is one in Berkshire - between 2 gravel pits (hence the subsidence), looks nice and straight and smooth but there are ripples of about 6-8' duration just after the entrance to the Tarmac site which once had me totally out of the seat of my bike when i hit them at the wrong speed and the front suspension couldn't rebound before hitting the next rise.

If you zoom out and head north across the water (submerged gravel pit) the Henley Rd has just had piles and metal sheeting driven in and a complete new southern verge/embankment built to stop it sliding down the hill

Maybe helpful to give us a link?

It escaped

https://goo.gl/maps/JxrvZ5zUNk12

Looks lovely and smooth doesn't it

[drm567]

Many of the minor roads in the Somerset Levels have the same problem. I pulled into this entrance to give way to a big artic (probably loaded with peat), it's motion as it came towards me (at under 20mph) really showed just how uneven the road is. Irritatingly the dashcam recording has only just overwritten.

[Ruperts Trooper]

We are a bit further north here in Scunthorpe, but the M181 suffers from what you describe with ridges forming which then have to be scalped and resurfaced. There are also some roads around the back of Epworth (basically south of the M180 between J1 and J2) which suffer in exactly the way you describe. Way back when in a company car great fun, but can imagine lethal on a motorbike.....

The A42 suffers from subsidence due to coal mining although fairly long frequency.

[Ruperts Trooper]

Many of the minor roads in the Somerset Levels have the same problem. I pulled into this entrance to give way to a big artic (probably loaded with peat), it's motion as it came towards me (at under 20mph) really showed just how uneven the road is. Irritatingly the dashcam recording has only just overwritten.

It's inherent cause is the same - drainage of fens several 100 years ago causing the surrounding land to dry out and drop it's level.

[Herned]

I went along this bit https://www.google.co.uk/maps/@52.74593 ... 312!8i6656 at what I thought was a sensible speed thinking it was a nice long straight empty road. It isn't. And I came close to needing new pants and ending up in the river

[Fenlander]

I went along this bit https://www.google.co.uk/maps/@52.74593 ... 312!8i6656 at what I thought was a sensible speed thinking it was a nice long straight empty road. It isn't. And I came close to needing new pants and ending up in the river

If you think that one's bad try it's twin the other side of the river. In fact jump straight across and look at the 90degree bend, you can't tell due to the height of the streetview camera but the bend is blind until you come over the crest off the bank before it, thing is at normal speed you need to be breaking before the crest to make the bend.