Motorway gantry sign
A gantry spanning the motorway with blue overhead signs indicating one lane exiting and three continuing ahead, and the following text.
Left lane destinations: M40 w ; Birmingham; Oxford.
Right-hand three lanes destinations: London (W), Uxbridge M40 e; Watford & (M1); Stansted [Airport symbol] (M11) M25 .
Junction number: 16.
Junction 16 comes in two parts - this is the first exit, towards Oxford and the Midlands, but you'll need to stay with the M25 a moment longer if you want London. If you're in lane 2 watch out for last minute lane changes made by people who think they want the left lane and then suddenly realise it doesn't go to Uxbridge.