the problem with covenants that come with houses is that they are often archaic and historical, and as far as i know (although i could be wrong - often am) they are enforceable by the people who made them (probably the original developers) You are unlikely to find the original developers still in business, or if they have been taken over, anybody who actually cares. Are you seriously saying that on the whole estate there is not one single person who aprks on the road overnight except your neighbours?, and that no-body has done for the last 37 years? What about people who DON'T live there - would they be allowed to park on the public road as the covenants don't apply to them?
In my opinion, they way forward is to talk to the neighbours