Road + Rail shared alignments?

[d5509]

. .

For one thing, I would like to know if we have any opportunities to get new rail links into our cities by stacking roads and railways on top of each other through the densely developed areas where new land take cost is potentially prohibitive.

. . .

Going back to HS1, from Dagenham westwards this is mostly routed in tunnel under existing rail lines.

The early London tube lines aimed to follow the roads above as far as possible, as that right of way was free, whereas, passing beneath private property was not.

I guess you are talking about a sort of co-operative new build road/rail route on the surface?

 

[biggus]

I guess you are talking about a sort of co-operative new build road/rail route on the surface?

That is the most probable scenario.

However it is entirely possible to build an elevated deck over an existing road without closing it. Seen it wiv me own eyes guv. Monopiles/piers are installed and then the bridge deck is jacked out and extended to span them. Apparently the term is "span launching".

Obviously a lane or two has to be temporarily closed while the piles are being sunk along the median... but if one lane of the M4 can be permanently closed for a bus lane...

I understand that some piling techniques are relatively quiet, and fast, and could probably be done at night if not in a residential street, enabling the road to be fully reopened during the day if required (depending on where you park the machines).
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When the Kyle of Lochalsh line was disrupted by a landslide, this also affected the A890 (I think that's the number) so as a temporary solution, the road was rerouted on to the railway using material so as not to destroy the railway for a distance.

Ah, I see from this news link that the line did indeed remain open to rail. Splendid!
http://www.obantimes.co.uk/2012/03/19/stromeferry-road-traffic-diverted-on-to-railway/#more-3398

 

[MK Tom]

It's quite common nowadays to try to share corridors to minimise the environmental impact of road building schemes. An example is the 2007-built A4146 which runs alongside the WCML between Bletchley and Leighton Buzzard. When Milton Keynes was planned the new A5 was routed alongside the WCML near Central MK to save space and avoid slicing grid squares in half. Also a lot of the M1 in Leicestershire was routed alongside the Great Central Main Line to take advantage of its straight alignment, but the railway closed nine years later so it's hard to tell the motorway wasn't first now.

 

[transmanche]

This example is not from the UK, but I think this is the type of scheme you're thinking about: the Mandurah line of the TransPerth network in WA. For a lot of its length, the rail alignment is in the central reservation of the Kwinana freeway. Similarly, the Joondalup line, where the route uses the central reservation of the Mitchell freeway.

 

[jopsuk]

the sheer width of that first one is incredible- looks like hard shoulders to both sides of each carriageway, each of which is four lanes wide. I reckon you stick a six track mainline up that central reservation.

 

[transmanche]

the sheer width of that first one is incredible- looks like hard shoulders to both sides of each carriageway, each of which is four lanes wide. I reckon you stick a six track mainline up that central reservation.

I think the additional hard shoulders on the offside are to allow for evacuation of passengers from a train if necessary (there are emergency access points at regular intervals).

Also, the track gauge is only 3' 6", which may distort your perception of how wide the trackbed is.

 

[34D]

There was a considerable section of the Great Central which ran alongside the M1 between Rugby and Leicester. It can still be easily seen on the west side of the motorway.

Also a lot of the M1 in Leicestershire was routed alongside the Great Central Main Line to take advantage of its straight alignment, but the railway closed nine years later so it's hard to tell the motorway wasn't first now.

Between which junctions is this please, and is there anywhere it is particularly obvious to see?

 

[CarltonA]

Between Junctions 20 to 21 for about eight miles or so. Easier to see in the winter due to the alignment being overgrown. Lutterworth to Leicester driving north on the left, though best if you are a passenger.

 

[biggus]

This example is not from the UK, but I think this is the type of scheme you're thinking about: the Mandurah line of the TransPerth network in WA. For a lot of its length, the rail alignment is in the central reservation of the Kwinana freeway. Similarly, the Joondalup line, where the route uses the central reservation of the Mitchell freeway.

Thank you, an excellent example, and a prime demonstration of the value of putting pictures in a thread, which I shall try to emulate with an illustration showing an elevated deck being built over a busy road.

Here is an example of the WMATA Silver Line extension in Virginia. I have driven my car right underneath the machine in these illustrations (or its twin) and I think it likely that it was working at the time to extend the deck.

 

[DXMachina]

M1/GCR alignment north of Lutterworth is even more obvious on Google Maps satellite view than from the M1 itself.

 

[Andyjs247]

Surprised no-one has mentioned the High Level Bridge in Newcastle.

Also various newish road alignments and by-passes, for example the A49 south of Leominster, A354 around Upwey near Weymouth and the A361 around Frome.

 

[Welshman]

Surprised no-one has mentioned the High Level Bridge in Newcastle.

Don't be surprised - have a look at #8.

 

[Clip]

Another excellent example of building over roads and in roundabouts - check thread in other transport too - is also on the DLR at Blackwall and East India stations. Then look at Canning town with its double deck platforms with the Jubilee line. Its possible and for light rail really should continue to make use of existing space above ground.