Draft representation:
Dear London Borough of Barking and Dagenham,
I challenge liability because the alleged contravention did not occur. I approached the box in lane 1 and a red car war travelling to my right in lane 3, which is the lane for traffic travelling round the roundabout rather than taking my exit. The red car unexpectedly cut across my lane and took the place beyond the box that I had reasonably anticipated would accomodate my car.
In the circumstances the contravention did not occur, and I invite you to cancel the penalty charge.
Yours faithfully,
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