Not as quick as me going down the M4 at 3 in the morning through roadworks with, you guessed it, no bugger doing a spot of work.
Used to be part of my weekly commute for a summer, Harwich to Exeter 300 miles.
Sometimes 8 hours down on a Friday, usually just under three hours home leaving 3am on Monday with one petrol stop.
Before those annoying limits and cameras.