Motorway gantry sign
A gantry spanning the motorway with blue overhead signs indicating one lane exiting and four continuing ahead, and the following text.
Left lane destinations: A30; [Hollow triangle diversion symbol] [Hollow circle diversion symbol] London; (W) ; Staines; Hounslow .
Right-hand four lanes destinations: (M4, M40, M1), Heathrow [Airport symbol], Watford M25.
Junction number: 13.
Just before this junction we cross the Thames and find ourselves north of the river. Have a look to the left as we cross and you'll see the bridge parapet is a classical ornamental balustrade - a leftover from the fact that the bridge is a much-widened version of one originally designed by Edwin Lutyens before the war.