Dieppe

Dieppe is a city in northern France. It is possible to hitch a truck going on the ferry to Newhaven. See this link.

Ferry to Newhaven (Personal Experience)

I'd heard before about hitching cars so I tried waiting infront of the passport control. Someone picked me up but as they'd made a reservation, the control kicked me out when they saw I wasn't on the ticket! Then they tried to charge me 65 euros to cross as a foot passenger! After I kicked up a fuss they brought it down to 50, still outrageous but after failing to get a lift to Calais (very difficult route) I had to pay it.

I think if you go into the office with whoever books, it is possible to get in a car for free.

Ferry from Newhaven (Personal Experience)

I travelled from Newhaven to Dieppe on the ferry (around £25 as a foot passenger), taking the night ferry which arrives around 3am. As prices are nearly all based on named people on a ticket, rather than per car as on other routes, you cannot hitch a ferry here, since you won't be on any named ticket. You could approach people who are approaching the ticket office, to add you to their car, but that is difficult.

I walked from the port to Avenue Gambetta which leads onto the Avenue des Canadiens (turn right after leaving port). Its a 2km walk and you simply walk along the coast passing over one bridge. Walk up Gambetta until you get to a petrol station. I had a sign Rouen/ Paris, and got a lift within 20 minutes. If you get an hours sleep at the port, get to the road early to catch the workers heading South.