Road Infrastructure Renewal

[MotCO]

The elevated section of the M4 from London was opened in 1959. I appreciate that it is maintained, but when will it have to be entirely renewed? The impact of such a renewal would be horrendous, but presumably it will have to be done at some stage?

Likewise there are other complex road structures which I assume will have to be renewed, for example Spaghetti Junction, but what will be done to minimise the impact?

 

[PeterC]

I would suggest a specialist roads forum such as this one:
https://www.sabre-roads.org.uk/forum/

 

[yorkie]

I would suggest a specialist roads forum such as this one:
https://www.sabre-roads.org.uk/forum/

We have a few people here who are also SABRE readers or contributors (I think @snowball @eastdyke @swt_passenger @nickleics @plymothian @PermitToTravel @maniacmartin and possibly others), so I wouldn't rule out an answer appearing here

 

[Cowley]

It’s actually a really interesting subject and I’ve trawled through the above website looking for information at times (my Dad was involved with building the M4 and M5 when I was little).

 

[Bald Rick]

Well, the design life of such things will be at least 100years.

Then again, Brunel’s bridge over the Thames at Maidenhead has managed perfectly well for 179 years, and is doing a job that not even IKB himself would have imagined.

Whilst in the road world, the Clattern Bridge in Kingston is approaching 850 years old, and still going strong.

I’d say the elevated section of the M4 has plenty of life left.

Incidentally, the elevated section of the M4 was opened in 1965. It was only the Chiswick flyover that was opened in 1959.

 

[175mph]

We have a few people here who are also SABRE readers or contributors (I think @snowball @eastdyke @swt_passenger @nickleics @plymothian @PermitToTravel @maniacmartin and possibly others), so I wouldn't rule out an answer appearing here

And myself, too, although with a completely different username to here.

 

[edwin_m]

It cuts both ways. The elevated M6 in Birmingham needed major repairs a few years ago, well under its design life, because of "concrete cancer".

Masonry bridges tend to be over-engineered by definition and can often take far heavier loads than they were intended for. Basically if you build an arch and infll it so it stands up and supports a level surface, and get the abutments right, it will also be able to bear a huge load. More modern structures are actually designed in the sense that people decide how much material is needed to support the intended load and don't include any extra. This means they are more likely to have problems if subjected to something the designer didn't expect.

 

[birchesgreen]

The Gravelly Hill Interchange has been undergoing repairs for years, must be nearly 10 years since they started.