Pruning of trees at top of Ealing Road

Why are Hounslow Highways pruning the trees today? It is Spring, the leaves are about to show, birds are starting to nest (magpies and crows use those trees), insects are appearing. The Arboricultural Association states that trees should not be pruned at this time of year and yet these trees are being given the hardest cut of all. How do you choose when to prune so hard? Why not in winter/autumn when the tree is resting? Why now when nature is about to get going and some of the few mature trees we have in the are being pruned so hard? It is extremely upsetting. I would like to know whose decision this is and why you do not seem to respect the natural rhythm of the cycle of nature.