1. The first thing you need to realise here is that all the rights of each party in this situation flow from the fact you own the land on which the driveway is and your neighbour has a right of way over this drive. This means that your neighbour can drive over this drive to reach his own land. However, it does not give him the right to park there. Your neighbour is not under any obligation to maintain this driveway as it is yours.
2. You are under an obligation to maintain the driveway and to keep it clear of anything which might interrupt your neighbours passage over the driveway. So your neighbour is within his rights to ask you to remove anything parked there if this interferes with his right of access. His right of access is both by car and by foot. Any argument that it only includes by foot will fail, as old rights of way are interpreted in a modern setting.
3. The bot***** *****ne is that you cannot stop your neighbour using your driveway as he has a right of way over it. If you do so, then legal proceedings might ensue and you will end up paying costs.
4. You cannot interfere with his free passage. This means that you cannot park vehicles on your driveway. You need to find an alternative location for them, or create an alternative space where your car can park.
5. Please Rate the answer, Suzanne, as unless you do so your expert does not receive payment for answering your question.
6. That sums up the situation nicely. You cannot park on your own drive but you can put up a sign to ask all others not to park there. Your solicitor who acted in the purchase of your property should have explained the situation to you. This is a basic issue which would arise during a conveyance.