TRAFFIC: Can you tell me the rules?

Could someone tell me the rules for turning left at the Wardentree Lane traffic lights, approaching from Pinchbeck.

When the green arrow isn’t on and I wait (whilst those wishing to turn right have the green light and are waiting for any traffic heading to Spalding to pass before proceeding) I have been verbally abused and have narrowly avoided being hit by those coming up behind me.

I have also had drivers just pull out and drive round me while I wait for the arrow to come on.

If I have right of way because I’m turning left, what is the purpose of this arrow which just seems to cause confusion?

Having read Highway Code, I can find no information relating to this scenario. Any information would be of great help as I’m beginning to fear going for my weekly shop at Morrisons.

Carole Cracknell

Pinchbeck