I watched few videos in internet as well as learnt from experiences of friends about fall of persons on the road while walking / driving two wheelers when they were hit by sudden opening of the door of cars/trucks by its inmates.
I feel, it is better to have slide type doors for the vehicles. This type of slide doors shall be made mandatory atleast on the right side of the vehicle where 'drive left' is followed and on left side where 'drive right' is followed. This is, presuming car/truck inmates try to open the door(s), after the vehicle is parked left / right as per the local rules.