Driveway on green area

BuzzFish

Hi folks,
I'm looking for a little advise on making a driveway in front of my house (along with my neighbour). We are in end houses of a cul-de-sac with a green area that's pretty much unused in front of our houses. The developer is still on site and the estate has not been taken over by the council. Just wondering if this is a non-starter of if there is a way to try to make this happen. The number of cars in the cul-de-sac each night means that cars spill out into the narrow entrance road. Maybe worth noting that with parking on both sides of this entrance there is a hazard for ambulance etc if they ever needed to get in and would be blocked. From google earth you can see the green area in question, there is no walkway access to the adjacent land, nor is there plans for this:

Current land boundaries look like this (I have marked where we plan to put driveways:

.... and this is how we would see it (possibly) looking:

Has anyone experience trying to get something like this done and if so:

• Is there any hope of actually being able to do this in anyone's experience?
• What are the steps; planning and then procure land or visa versa?
• Do we need to try to purchase the extra land from the developer and would he be allowed to sell it as he's still under bond?
• Do we need to wait for the council to take over the estate (could be a long time)?
• I assume planning would be required but would this be just to drop the kerb or for the full build?

Many thanks in advance for any advise.