Ray
Have a look at
www.silhouet.com/motorsport/tracks/rouen.htmlThen click on the road map link.
Original - 1950 to maybe '53 circuit northern straight is the D 132a, marked "l'Etoile".
The circuit can be driven in that configuration by you or me tomorrow.
The curly bit between l'Etoile and the motorway is the '70s top straight. We can walk that bit but it's blocked off from Motor traffic as it's now a joggers', cyclists' and dog-walkers' paradise. Tarmac and curbs are still there.
The real - mid 50s to late 60s - top straight was the N 138, wrecked when they built the motorway. You can drive most of it, but it comes to a dead end before it would have re-joined the old circuit. Curiously the N 138 becomes the Mulsanne Straight at another circuit miles to the south.
The buggers have laid tarmac over the Nouveau Monde cobbles and knocked down the (decaying) pits and roofless stand,but the steps up into the spectator banks are still there, and believe me the curves are VERY daunting down from the old pits and up the hill. A must for any 50s or 60s enthousiast.
As for the 405, well unfortunately the french police timed it at over 110 mph Easter 1999, just north of Bordeaux. My wife was driving, I'd warned her as to where the radar would be, and I paid the 600 ff fine.
OK I'll get up really early for my Christmas lap this year. Got to respect those 1907 guys though.
Kpy