In London where pavement parking is theoretically illegal everywhere unless allowed the councils seem to be trying to regularise parking arrangements, either by enforcing the ban on exiting ban on pavement parking or by allowing parking through legislation and white dotted lines along the pavement. I was pleased to see that when Houslow recently consulted on allowing parking officially on Gould Road that they made it a requirement that 1.5 meters should be retained for pedestrians.
Gould Road, Houslow
Bays have been created in other places with considerably smaller space left for pedestrians. I was trying to find an example, in Waltham Forest I seem to remember, where there was only 700mm left of pedestrians which is less than the width of a doorway! I will update this post if someone can give me a link to the post.
Incidentally, according to the current law as it applies in most of the country outside London a car is only causing an ‘obstruction’ if someone is actually being obstructed. And then even if it is impossible for that person to get past on the pavement the police may determine that they can simply use the carriageway instead as was the case in Bristol in this example which the police said was ‘not obstructing the highway’!
Not obstruction!
Pedestrian Liberation 
That photo is just unbelievable. Or at least it should be, unfortunately, I have plenty of photos just like it. The police just aren’t interested.