Re how to get there.
By train, it is far quicker and easier to go via Lille, and if under 25 cheap (£230 in 2004, and first class was only and extra £30, and includes free food and drink). Some may want to sightsee.
For driving, I have a list of the Gatso sites, but I can't work out which way they face. Nowadays, you probably need gps coordinates too. Any use FS?