Heading east from London? Visiting the Docklands, Lakeside shopping centre or Southend Pier? Take Billy Bragg's advice, then, and hitch a ride on the A13.
If you've ever been on the M62 across the Pennines, you'll know the one. It's the huge arched bridge 120ft above the road. And this is what it's like when you're standing on top of it!