Didn't really expect exact width as being relevant here but have just checked a couple of andrewr's measurements and am getting values that are up to 10cm different either way. So, without wanting to get into who has the better tape measuring skills, and one can't ignore bias in this, can we agree that the pavements are the same width +/- 20cm? :-)

On that basis, I still don't see why it would be appropriate to allow parking on the pavement of Devonshire Road whereas it isn't on Honor Oak Park.

On the rat run issue, I don't think there is a solution that will please everyone. I am wondering about the merits of just blocking the Forest Hill end. The evening rush seems to create the biggest nuisance that end and it is a dangerous junction anyway.