When traffic lights are green, when should a driver not proceed?

When oncoming traffic is waiting to turn left.
When traffic is stopped waiting to turn from the road on the right.
When it would be unsafe to do so.
When traffic is stopped waiting to turn from the road on the left.

Explantion: Although a green traffic light means proceed with caution, you should not enter a junction if the way is not clear or if by doing so you would cause an obstruction to other road users.

Theory Tester

When traffic lights are green, when should a driver not proceed?

Control of Vehicle