I was driving along recently when someone in a parked car decided to fling their door open: right in my path. Fortunately, I managed to swerve out of the way (and, happily, without getting into the path of anything oncoming in the opposite direction).
It made me think about why vehicles actually need doors on both sides. (You could, for example, have a rear-facing loading ramp but that makes getting Granny in the front rather difficult).
Today’s invention is to build cars with no offside doors. This would eradicate the danger people face when standing on the roadway, fiddling with their keys or a childseat, as traffic surges past. It would also hugely strengthen the bodyshells of vehicles, leading to improved safety in collisions. We already make left/right hand drive variants, so this would be just another of those.
This approach would mean that bench seats would have to make a comeback and that Granny would have to remember how to slide along them.