Without knowing where you are located, why fly? Down to London, Eurostar to Lille, over border by local train, done. As for getting about, it will be a mad rush but all part of the fun. In recent years the plot has been find a good café/restaurant somewhere on the parcours (they almost all show the race on TV), get beers musselen or kip and frites sorted out, nip outside to watch the race, back in to see the rest. Real fun in a group with an unofficial sweep for the winner by team. Winner takes all - just like a race. Have fun anyway, it's a much better day out than riding in the race!