M5 queuing due to traffic lights

I am writing to express concern about the work taking place at J12 southbound exit slip road. The work has been going on for some time with no problems.

However in the last week, it would appear that the traffic light settings have been changed. Whilst previously these would allow approx 25 or so cars through, they now only stay green for long enough to allow 5 cars max through. The roundabout looks clear from other approaches so I cannot understand why this has been changed. At peak times, the result of this is that there is now a queue of about half a mile of traffic on the motorway itself on the inside lane. The hard shoulder is closed so the traffic queue is building on the motorway lane itself.

Sitting in that lane feels like being a sitting duck as the rest of the traffic hurtles past. The closed hard shoulder and the change to the traffic lights has made a very dangerous situation. Having now experienced this for the third day running, and particularly in light of the awful accident further up the M5 in the last week, I feel compelled to draw your attention to this before there is a serious accident. I hope you will give this your earliest attention.