A51 Aix–En–Provence–Gap–Grenoble, France?

[Chris56000]

Can anyone tell me anything about this missing section of the A51 in S.E. France?

Has a projected route for it appeared on any Michelin/IGN or French Road Atlas maps?

Is it likely to ever see the light of day?

I came across it whilst planning our holiday route back from Italy into S.E. France last night!

Chris Williams

[KeithW]

Can anyone tell me anything about this missing section of the A51 in S.E. France?

Has a projected route for it appeared on any Michelin/IGN or French Road Atlas maps?

Is it likely to ever see the light of day?

I came across it whilst planning our holiday route back from Italy into S.E. France last night!

Chris Williams

The usual things - money and politics, the main problem seems to the mountainous section north of Sisteron where plans to complete the route attracted protestors on environmental grounds. It was supposed to have been built in 2006 but it never happened
See
https://en.wikipedia.org/wiki/A51_autoroute

[danfw194]

It's a shame this has never been completed. It would have made a viable alternative to the A7 between Lyon and the Riviera, which as we know can get pretty clogged up in the holiday season. To be fair, the fact that it has been built to the extent it has is relatively impressive, at least in my eyes.

[Bryn666]

It's a shame this has never been completed. It would have made a viable alternative to the A7 between Lyon and the Riviera, which as we know can get pretty clogged up in the holiday season. To be fair, the fact that it has been built to the extent it has is relatively impressive, at least in my eyes.

The oldest southern most section of the A51 dates back to the early 1950s, it was only really much later the alt-A7 idea north of Aix came to the fore. The big problem with the corridor as it currently stands is traffic following from the south has to either traverse the notorious Rampe de Laffrey (banned to large vehicles) or take a detour via the mountains across to the D1075 (look at a map, it's not easy). The two disconnected sections do not point at each other rendering the northern section out from Grenoble currently underused which makes it very hard for the concessionaire to propose finishing it.

More info here: https://routes.fandom.com/wiki/Autorout ... Historique

[M19]

Another gap is the A84 at Avranches where it becomes the N175 when bypassing the town for a short stretch. It’s not a massive issue really. The A84 is also not tolled.

[Bryn666]

Another gap is the A84 at Avranches where it becomes the N175 when bypassing the town for a short stretch. It’s not a massive issue really. The A84 is also not tolled.

A lot of these gaps are where a town's bypass is much older than the autoroute either side or where plans changed and a road is missing. The gap in the A43 around Chambery where the N201 fills in is an example of missing road syndrome, and the former N23 through Angers is an example of old bypass (throughpass in this case) with motorways plugged in later.

The A51 is the only truly egregious gap in an autoroute because it's completely disconnected and requires backtracking to get back to either part.

[Chris56000]

Can anybody point me in the direction of readable proposed route maps?

I found a "Dossier Du Debat Public" from a link on the Sara Autoroutes Wiki page but the maps on it have been so appallingly compressed that they're just an unreadable błocky mess, and I'm not well up enough on G.I.S. to be able to re–create them!

Chris Williams

[SouthWest Philip]

Another obvious gap in the autoroute network is the A28 past Rouen. Should the disconnected parts of the A28 ever be joined together I would imagine a western bypass and some rerouting via the A151 would be involved?

[SouthWest Philip]

With regards to the A51, might be just see it tidied up be making the northern section an extension of the A480 or A48?

[Bryn666]

Another obvious gap in the autoroute network is the A28 past Rouen. Should the disconnected parts of the A28 ever be joined together I would imagine a western bypass and some rerouting via the A151 would be involved?

Nope, they're going to the east and joining the A13 there - it'll connect more towards the A154 as there's a lot of traffic aiming for the A10/A11 from Calais that is now going this way to avoid Paris entirely.

https://contournement-est.fr/les-cartes-du-projet

[RichardA35]

Had a pleasant return journey on the southern part of the A51 from La Saulce to Aix on Monday this week while visiting a relative near Marseille. For me, most of my journeys in the area have historically started or finished near Briancon, so access to stations or airports at Nice, Marseille or Avignon are fine and are not compromised by the misssing stretch.