If you want to get bored out of your skull, with all the stop-starting due to umpteen traffic lights, potholes, people wandering around the middle of the road wearing nighties, numpty taxi drivers left hooking you, and a dense stink of cheap cooking oil from all of the fast food joints filling your nostrils, then set off from Marble Arch and just head straight up the A5, cut through St Albans, up the A1081 and 2 hours later, you're in Harpenden.
But what will you have achieved apart from a vague nasty taste in your mouth from all the car fumes, and possibly one of Davy's reject kebabs stuck to one of your tyres?
Lots of other options - here's two:-
If you head out from Enfield Station for example, then you can route through some lovely countryside north passing between Hertford & Welwyn Garden City, then turn west to go through Old Welwyn or Knebworth, through Ayot St Lawrence and then Harpenden.
Alternatively hop on a train to Mill Hill, back roads through Borehamwood, across to Hemel Hempstead, Redbourn, Wheathamsptead, Ayot St. Lawrence, and then back to Harpenden.
(I did a sort of similar 'pay homage' thing to Henry Moore one time, deliberately aiming for Much Hadham en route to somewhere adjacent.
