The Vietnamese population are still suffering the aftermath of the War and there are a lot of handicapped people. Nonetheless, few things are adapted for them. Usually they are looked after by their families, or by the orphanages.
This is one reason why handicapped travellers are not a priority for the Vietnamese, so you are recommended to organise your trip as much as possible.
Vietnamese culture has an impact on how they perceive handicap because it is said that "destiny" controls whether families have handicapped children. Handicaps are "explained" by bad karma, or a malicious spirit, which is why families with them are often pointed at.
Handicap International's projects are designed to encourage better social and economic inclusion of handicapped people.
The pavements are crowded with cars, motorbikes and street sellers. Their height is also not adapted to wheelchairs.
Public transport, like buses and trains, is not designed to be used by handicapped people. Internal flights are a quick way of getting from north to south Vietnam.
If you want a pleasant trip to Vietnam you really have to book a car and driver in advance.
Concentrate on Vietnam's towns: Saigon, Hanoi, Hoi An and Hué, where the hotels have lifts and so are accessible. Some boat trips are possible in these big towns, you need to ask when you reserve the trip and ask for restaurants that are accessible. For example, Hoan Kiem lake at Hanoi is somewhere where you can go on foot or by wheelchair.
The Vietnamese, who are always helpful, will be a valuable aid.