In reply to stevev: Last year I walked up from the road head in Les Houches. It took nearly six hours to get to the “Camp de Base” at the Tete Rousse. This was mainly because I am old, but it was very hot, the sacks heavy with camping gear etc. Taking the lift to Belle-Vue would only have saved about two hours. The next day I left the tent before 01.30h, arriving on the summit before 07.00h Conditions were perfect and there was a very good track in place. I got back to the Tete Rousse before the afternoon crowds starting ascending to the Gouter hut.
I do not know if theses times help as it all depends so much on conditions and the person. For example, a few days before my ascent a Spaniard took just two and a half hours to get to the summit from the road head in Les Houches. He was training for the Mont Blanc Ultra-trail.
Incidently, this summer will be the 150th anniversary of the first complete ascent of the Gouter Ridge, also known as the Voie Royale. I am hoping to celebrate this by starting from the road head in Bionnassay on the 17th July, weather and conditions permitting