from a person who works for firstgroup i can tell you that the most probable reason for the changes are due to vandalism to buses ie- youngsters throwing bricks/rocks through the windows regardless of passengers.it is costing the company more in repairs ie-1 window can cost upto £2000.the only other alternative i can suggest is that after 7.o clock all buses stop going through the estates & stick to the main roads,these new double deckers on the 41 route are not 6 months old yet & they are in a terrible state (slashed seats,scratched windows,broken camera's,burned seat backs,holes in the ceilings caused by punching etc)