Sorry to confuse this discussion with a few facts, but here goes!

The pavements in Devonshire Road are generally 2.3m wide. I haven't done a detailed survey but that is the width outside nos 46 and 59 at the Forest Hill end, and 312 and 255 at the HOP end. I also checked it in one place in the middle where it was also 2.3m.

By comparison, outside 121 Honor Oak Park, where pavement parking is permitted within the marked box, the pavement is 2.1m wide. Taking the box into account, 1.2m is left of the pavement. This may not quite be the narrowest bit of pavement, but it is certainly narrower than the vast majority of Devonshire Road.

lacb's reference to the TfL paper is interesting. Although this shows that there has been a marked increase in the proportion of journeys by public transport, the reference shows that the number of journeys using a car for part of the journey is virtually the same in 2007 as it was in 1993 (10.3m / day vs 10.6m - table 2.3). Although car journeys peaked at 11.1m in 1999, they were virtually constant from 2003-2007. The frightening thing is that the total number of journey stages has increased from 22.9 to 27.8 in the same period with most of the increase being taken up by public transport, not walking or cycling which remain very much minority modes of transport.

I'm not saying that marking the pavement will solve all the problems in Devonshire Road, but I think it would help if strictly enforced. It would stop stupid parking on corners and parking too far onto the pavements so as to obstruct pedestrians. It would also help on bin days when residents could put their bins on the edge of the pavement between the boxes leaving the inner part of the pavement clear for pedestrians.