I am thinking about using a shuttle ( for the first time) from my hotel in Paris to CDG.
Will they stop and pick up other people on the way?
One has to be at the airport at a certain time ,of course . Is it better to just take a taxi ?
It will be Friday morning in the rush hour so I am worried that a cab can end up costing more than a shuttle ( 55 euros) .

Shuttles may very well have additional passengers to pick up, or it could be that you are the last one picked up. They will generally tell you what time they will pick you up, based on your flight#/departure time. If you don't think it's early/soon enough, you won't convince them to come any sooner.

Would you be able to cab to one of the pickup points for the Air France coaches or the Roissybus..?

thanks travelut.

I will most likely do as you suggested.

We took parishuttle to CDG twice. One time we were the last to be picked up; one time we were the first of three to be picked up. Both times they got us there with plenty of time to spare.

Honestly, if I had to do it again, I would probably take the train, taxi, or bus, as mentioned above.

My advice is to request your hotel to reserve a taxi the day before departure. I've read bad stories of some shuttles not picking up the clients as arranged and that resulted in the clients being late to the airport.

Honestly if I were you and wanted to take a shuttle over a taxi I'd do so upon arrival at CDG to get to the hotel, but not the other way around.

thanks.
I am arriving from Amsterdam by train so my concern was leaving
the city. From what has been said , I infer shuttle might not be the best option...

For myself getting from CDG to the city center it's okay to use the shuttle because if something goes wrong with the reservation or they have other passengers to drop off at least you have time to spare.