M4 4B Thorney Interchange

Layout and signage

Watford (M1 Link)
Birmingham (M40 Link)
Heathrow Airport T4 & Cargo
Gatwick Airport (M23 Link)
Winchester (M3 Link)
M25 Link
  M25
(M1)
(M40)
    M25
(M3)
(M23)
  Heathrow Airport T4 & Cargo
Gatwick Airport (M23 Link)
Watford (M1 Link)
Birmingham (M40 Link)
M25 Link

Lane configuration

LanesLanesLanesLanesLanesLanes

  • Lane 1 exits and returns after the junction.
  • Lane 2 continues ahead.
  • Lane 3 continues ahead.
  • Lane 4 continues ahead.

LanesLanesLanesLanesLanesLanes

  • Lane 1 exits and returns after the junction.
  • Lane 2 continues ahead.
  • Lane 3 continues ahead.
  • Lane 4 continues ahead.