Shared driveway

Hi;

Problems with shared driveways are pretty common. The obligations and rights of the shared driveway are governed by an easement over one or both of the properties. It's likely that the easement straddles the property line giving both you and your neighbour free and clear access of that portion of the driveway so that you can both access the back of the property (usually to access garages at the back). In some cases the easement is on only one of the properties giving the other property access over your land to get to the back. 

In either case, if an easement does exist that gives one or both of you rights to the other's land, it will be for egress only. That is, it is for the purpose of traversing the land to get to the back. Not for parking, because parking means blocking, and that violates the use of the easement.

Your best bet in these situations is to try to come to an amicable agreement with your neighbour, because your alternative is to hire a lawyer and take legal action. that's expensive.

First, get a survey of your property which will show the location of the easement. Also, your property ownership documents should contain the description of the easement (the deed and/or parcel register). This will tell you exactly what the easement is for and what your and your neighbour's rights and obligations are relative to the easement. Armed with these you should be able to have a conversation with your neighbour and hopefully convince them to change their behaviour.

If you're past that stage, then your only recourse is legal action. Hire a lawyer who specializes in boundary-related disputes and get them to handle it for you.