Edit: had a lawyer send a letter talking about how the easement doesn't allow them to use our driveway. We also put up some private driveway signs. It seems to have helped because they are using our driveway less.

We have this quad flag lot situation. Edit: I live in A. The neighbors in the corner at C have a lot of friends and family come over. Some of the time there are six cars parked in their driveway and front yard.

The lots are divided in two and there are two driveways. Total of four houses. So the people in the corner will often drive up my driveway to get to their driveway because their driveway is blocked by somebody else at that house.

We've had conversations with them several times. I even hired a lawyer to send them a sternly worded letter that says "hey the easement doesn't say anything about you being able to use that driveway and know that you might be prosecuted for trespassing". I put up a security camera and about 20 minutes ago somebody drove up my driveway to get to the other house.

I have asked in legaladvice and the answer was basically why do you give a shit about this. The easiest solution here is for me to not give a shit about somebody trespassing on my property. But it's really hard to not give a shit about somebody trespassing. Especially when they tell me that they're not trespassing that this driveway is a public street and they have every right to use it.

The Plat map is very clear, it's not a public street. The easement is very clear, nobody from that lot has the right to use our driveway.

Looking for suggestions for how to proceed with this.

US, Oregon

Edit: there is a gravel area at the end of the two driveways that my neighbor uses to turn her car around so she does not want to build a wall or any sort of permanent structure there that would make it harder for her to turn around

Edit: if someone is injured on my property I might be liable for their fees associated with that injury. That seems like a pretty good reason not to want somebody on my property that isn't invited.