Essentially there are two ways you can travel to the Etape du Tour 2015: by car or by plane and then rent a car. Of course, you could go an organised tour with a travel company, but we tackle that in our Etape travel tour groups article.
Driving to the Etape du Tour 2015
To my mind, travelling by car to an Etape is the easy way of getting there. That may seem counter intuitive and of course it depends how you do it but I would always choose driving above flying. It helps that I am setting off from London; if I lived in Aberdeen I might have a completely different view about the convenience of getting there.
In terms of the route, there are essentially two ways of getting across the Channel: the Eurotunnel or ferry. If you book far enough in advance you can take the Eurotunnel for around £45 each way and it takes roughly an hour, once all the faff of getting on and off the train is taking into account. Remember that if you have bike racks on the top of your car you need to book yourself into a high clearance carriage, which doesn't cost any more but there is somewhat limited availability so it may restrict the times at which you can travel if you don't get in early enough. The ferry is a bit cheaper - around £60 return if you book well enough in advance - but is substantially slower at around two and a half hours. If you've had a long journey to get to Dover the ferry can provide a welcome break in your driving though as going through the tunnel really lives no time for a quick restorative nap.
The drive from Calais (whether you arrive by tunnel or ferry) is relatively simple, although it's not exactly just round the corner at around 920km from Calais. Whatever you do, do not be tempted to go via Paris. I've done that once before and it is definitely not to be recommended. From Calais head east towards Brussels and then take the E15/A26 towards Reims. The E15 becomes the E17 and you keep following to Reims, then Chalons en Champagne, Dijon, Macon (by which time it has become the E15 again) and then head to Lyon. At Lyon you take the road around the north east of the city and head to Chambery, followed by signs to Modane and the Frejus tunnel into Italy (the E70). Saint Jean de Maurienne is off the E70 and is pretty easy to find.
For a car, last time I did the drive out in a VW Touran I managed it on two £80 tanks of petrol and it cost around 100 euros in tolls. So, including Eurotunnel the entire journey cost around £285 in each direction, or £142.50 per person. Obviously if you take a larger car or fit four people in the car then you can keep costs down a great deal more. From London we did the journey in just under eleven hours door-to-door.
Personally I like the flexibilty having my own car gives me. I have bike racks on my roof so with two of us travelling out we could take a spare bike in case of disaster. We could pack as much extra cycling kit as we liked - spare tyres, track pumps, every conceivable change of gear depending on the weather etc - as well as plenty of food that we know our bodies like. I am not sure I'd have packed baked beans and cheddar cheese (for a post ride recovery snack) if I'd be on a plane. I was also able to take a 2kg bag of muesli to tuck into at breakfasts.
The downside of a car is that it takes a bit longer, or at least in theory it does. Once you've counted the hours packing a bike box, getting to the airport early, sitting on a flight, hiring a car and reassembling the bike I am not sure how much time you really do save by flying. But I do know some people aren't as relaxed as I am about driving on foreign roads. Also, I was able to be a bit more relaxed about driving back. If you finish the Etape on Sunday afternoon and need to be back at work on Monday morning then driving isn't probably a realistic or safe option, given that if you're a bit knackered a 10+ hour drive home probably isn't that sensible.
Flying to the Etape du Tour 2015
I guess that most people from the UK will fly to the 2015 Etape du Tour. This will either be because they are on an organised Etape tour or because they assume flying will be easier.
There are five airports that are within reasonable distance of Saint Jean de Maurienne: Chambéry, Grenoble, Lyon, Geneva and Turin. If you're not part of an organised travel group then you will need your own car to get to your hotel or pay extortionate amounts of money for a transfer bus.
Of these, Turin might be the most surprising possibility to the average reader. But actually Turin airport is only about an hour and 20 minutes drive from the entrance to the Frejus tunnel on the Italian side and all-in-all is under two hours driving to Saint Jean de Maurienne, although there is a hefty tunnel toll to be paid to get into France (around 80 euros for a return journey!). Picking up a hire car in Turin is really easy and there will be relatively few people trying to get bike boxes on their plane to Turin so it might work out cheaper and easier.
Geneva is the obvious place to fly to because there are so many flights going there from airports all around Europe. It's a bit of a scrum when you get there and the distances to get around are a bit of a pain (between check in and the car hire, for example). And it's still a 162km drive from the airport.
Lyon is a 174km drive and there are some budget airlines that fly there. It's an interesting city to visit with great food if you have a bit of time after the Etape and want to waste some time before you fly (alternatively you could spend Monday morning tackling the other side of the Croix du Fer, given you will have got your legs into full climbing condition).
Chambery and Grenoble are much smaller regional airports and a shorter drive but they have not yet published their summer schedules so we don't yet know who will fly there. Chambery is normally served by British Airways from London and Flybe from Southampton (but perhaps only for winter skiing flights) and Grenoble caters for tons of skiing flights from the UK but is much less well served in the summer.
Read out guide on Hotels and accomodation for the 2015 Etape du Tour.