Some random thoughts, not thought through in any way.

Personally, I don't think that there is enough parking on Dartmouth Road. If the shops are going to be more successful then people need to be able to stop outside and run in. Forest Hill has ended up with some very big 'plazas' outside the job centre and paddy power which could be eroded slightly to become short term 30 minute parking for the shops. On the other side of the road the parking is a mess. It should be a red route down by (and including) the florist. Then there should be parking all the way along the road and they should get rid of those irritating chicane things.

If this isn't possible then I would make David's Road two way up to Sainsbury's car park. Then you'd be able to park quickly in the town centre instead of going on the magical mystery tour of Waldenshaw Rd.

They could do with removing the pedestrian island at junction of Dartmouth Road and south circular having two lanes onto the South Circular (left and straight on).