I went across Canada three times, down the West Coast of the US, across to Texas and down to Chihuahua. And then, a little while later, I got a lift from Escuintla in Guatemala to Mexico City and went on to Boston in four or five days for the Bicentennial, getting a lift in Tennessee from some doped up boys with a trunk full of guns. And then there was Dawson to Vancouver, where a woman in a van raced a car from me (I had more hair then) and demanded sex for the ride (it was the 70s, you had to be there....). Oh - and from Miami to Los Angeles in eleven days, which included getting put in jail, being assaulted by gay men twice, (I may have been hitching at some recognised pick-up point) painting a house, sleeping with one of my rides, getting picked up by the cops in a thunderstorm outside Dallas (cop 'I was in Liverpool during the war, with Mrs Thompson - d'ya know Mrs Thompson' DZ 'Mrs Thompson guv'nor, why she's like a muvva to me!!'), fixing a fuel line in a truck carrying fast-rotting oranges despite knowing nothing about engines, and driving through Palm Springs at 85mph despite never having had so much as a lesson because the driver who had jumped bail in Lake Charles Louisiana had, after 1500+ miles, run out of speed. I did do Boston to San Lucas Toliman in Guatemala in six days in the back of a Toyota Hilux pick-up truck, but since I had a half share in the pick-up truck that's not really hitchhiking.
I did hitch in the UK - getting to Leeds from Buckinghamshire in decent time, but once I'd cracked the same sort of distance on a bike there didn't seem the need. My last attempt was in 1993 on the A38 out of Plymouth. A complete failure. I'd have been there still if I hadn't walked to a bus, gone to the railway station and got on the sleeper to Paddington.
And if Patrick Stevens can beat that I'll take him off my ignore list.........