I think the clogging of local roads with people parking and looking for parking will do more than signage or 2 hours free parking to get people to use the local car parks. People will try to park off Dartmouth road, find themselves stuck trying to negotiate their way up and then find they spend 5 minutes looking for a space that is over 5 minutes walk away from Dartmouth Road. It will become quicker and a more pleasant experience to park at Sainsburys or PV and walk.
I occasionally go to Beckenham where the parking sign shown is and I'd say the reason people use the car parks there is no free on-street parking. I think it probably works better for the shops and the local residents as shoppers make the decision to go into town for the shops and a coffee and residents can park on their own streets. I don't think the Spa as a swimming pool suffers from people having to pay to park there.
There is a lot of parking around Dartmouth Road which residents and shoppers can't park on because it is taken up by commuters, traders in their silver mercs (okay only one ) and loads of white vans. Should we not be looking at some solution that gets rid of these people as well as well as using our car parks more efficiently?