This simple T-junction which forms part of the A3's transition between fast/inter-city and slow/urban road has a very unusual setup. As would be expected from the location, the traffic lights give most of their time to allowing traffic on the A3 to continue in each direction. On the southbound side, due to a shortage of space, this is handled by setting all the traffic signals to 'stop', and then including a green filter arrow for traffic heading straight.
A straight ahead filter arrow is rare in itself, but such arrows are normally used for minor turnings. In this case the little arrows are being used to control three lanes of the A3 mainline, while the remaining single turning lane for the A306 gets all of the signals dedicated to it, and no excuses for not seeing that it has to stop.
The junction was previously positioned to the east of here, but moved when the A3 was dualled.