Bit of an update. Got the re-routes done now, info via TNR website if of interest.
Tende switchbacks have re-opened to cyclists.
The damaged Roya valley is passable but has a 1-way traffic system, this from a local rider recently:
Along the road you have many parts that have been temporarily repaired
with gravel sections, not a problem for a TNR rider! The big problem
in this valley is that, between Saint-Dalmas and Fontan you have a 6
km long portion where traffic is one direction at a time.
At night and on week-ends, cars can go every hour between h00 to h15
from Saint-Dalmas to Fontan, and between h30 to 0h45 in the other
direction. On weekdays the road is blocked for works and only one
crossing at 12h00 downwards and 12h30 upwards is allowed from 07h00 to
I don’t know how it will be in September but seen the numbers of parts
of the road that have to be repaired, it would be surprising if it was
different. Maybe one may consider taking the train in Tende, it’s free
all this summer (but there are not many unfortunately).
Riders would need to respect the roadworks and the instructions they find there at the time - it's about safety as much as the reputation of riders. It's a downhill section, on gravel at the moment before the road is fully repaired, and traffic that way is reduced so I doubt it'll be a problem to ride through that 6km section.
You might need to plan for the roadwork delay so you aren't late to Nice if you have a flight to catch.
There are shortcut routes included from this area and from the Col Turini and the cafes in La Brigue are really nice if you have some time to relax there. I sat in the small park by the church for breakfast the last 2 rally rides.