Bletchleyite
Veteran Member
It is slightly bizarre why we have to be different. Most urban areas in the UK use single door buses, and it is painfully slow to alight/board passengers on busy services. Urban areas in most of continental Europe feels *generally* easier to travel around for this reason.
I'm very much in favour of dual door, but one reason it's not popular in the UK is the large number of routes which are "suburb to central bus station", and mostly only pick up on the way in and drop off on the way out. For those dual door doesn't really bring much benefit - for the gain you need a significant number of stops where people both board and alight. So they'd be of benefit to cities with only cross-city operation with distributed central demand, like Milton Keynes, and indeed the home of UK dual door, London. Edinburgh also used dual door for years.
There's one other case where it works, an actual rear door (rather than middle) encourages people to move down on busy single decker routes where a significant standing load is usual. And then you have routes like Oxford/Wilmslow Road in Manchester which really needs to be a tram but you can get a lot of the benefit with a long articulated or even double-articulated vehicle with 3 sets of doors and open boarding, basically a tram on rubber tyres on the road.