Theorem

Whatever the width of the pavement, Vietnamese pedestrians just do not care and will walk on the street anyhow”

I found a nice place for jogging from time to time – usually twice a week, at least once. The area has sparse traffic and large pavements, surrounded by gardens and trees. I find the sidewalk over there quite large in comparison to the rest of Hà Nội.
If you have never been there, here is the typical pavement in Hà Nội historical center: you cannot see it because there is none. And if it existed, it would be full of scooters and street vendors anyway. Hence walking safely on a sidewalk is not an everyday experience in Việt Nam.

But even when the pavement is 4 meters wide, pedestrians still ignore it, even at night:

Wait, and if this was just an adaptative behavior? could the sidewalk be more dangerous than the traffic in the street? have a look at the picture below.

Ok, for those who did not zoom in above, here it is with the flash: 1 square meter hole, direct access to the sewers.

This is maybe the reason why pedestrians prefer to deal with scooters. They are loud and have lights on at night.