NOW that the North Street/Cavendish Street junction has been upgraded, what is the point of the green filter light?

Surely the benefit of creating a third lane on North Street is to allow traffic to turn left into Cavendish Street whilst the other two lanes remain at red.

The filter light only comes on with the main green light, making it superfluous, so the situation is more or less as before which seems like an awful lot of work has been done for nothing.

IAN SHEPHERD Gamel View, Steeton