Working on the Railroad...ties

I can't help with the legal or disposal answers, but I have dug up a lot of ties and found the easiest, best way was to use a long (6-7 foot) digging bar to pry the tie from the ground. Use the point of the bar to create an access hole and get under the tie, then a small log or 4x4 as a fulcrum and you can pop them right up with minimal effort. A good pick or mattock is the next best option if a long bar isn't available.

It seems to me that they are already acting reasonable, right? Talk to them, tell them your plan. I think the best way to go about it is to dig them up yourselves (as a courtesy). (I'm a little confused as to why it would be difficult to dig them out. Are they horizontal to the ground or vertical? I bet a little wiggle/wobble and a pry bar and they'll come out pretty quickly.) Then, stack them in an unobtrusive spot on their property. Go about your business of improving your property while not making things obviously ugly or weird on their side. Talk them through your plan. I would not offer to get rid of the ties for them. They are their ties. Unless you are worried about them doing something unsightly with them, in that case, you could offer disposal as a courtesy, too. But you really don't want craiglist randoms tramping about your property and digging things up. So, you can offer them on the side of the road with a big "free" sign and/or on Craigslist for some amount of money (keep it). Or borrow a friend's truck and take them to the dump for a small fee. A weekend of labor and you just got 2 extra feet of property!

Wooden railroad ties are not used anymore, due to the toxic brew of chemicals that impregnate the wood. Investigate responsible ways to dispose of them if you remove them. I would not want them on my property, especially in any close proximity to kids, pets, or a garden with edible plants.

Yeah, ask. If they want them, they can help dig them up. If not, try the Craigslist route.

Yeah, I think you're pretty much stuck and have to talk with them. Let them know that you are putting up a fence and can either a) cut them or b) they can help dig them up. You wouldn't want to dig up anything that is on their property- even if it encroaches on yours. The fact is that the neighbors knew this day was coming and, unless they are crazy-folk, completely expect you to take your land back.

Just a practical note. Be careful with these things and do NOT burn them. Railroad ties in the US are almost always chemically treated to prolong their useful life. They often used nasty stuff to do this.

If these are truly old rairoad ties, and not 9x9 pieces of wood that are roughly shaped like and thus somewhat described by "railroad ties", then yes, do be careful about all the chemicals involved. I'd be more concerned about what you're going to do with all the gravel, and what might be underneath the gravel, than about the wood. By the time you get the actual driveway "paving" cleared up, the wood will not be nearly so deeply buried.

I would not offer to get rid of the ties for them. They are their ties. I would, even if I was morally in the right, in the eyes of the gods and surveyors. Dumping waste on your neighbor's yard as part of a building process you've initiated has a chance of mildly irritating them - you're pushing work onto their plates. These folk will be your neighbors for 30 years - their good will is more valuable than the cost of taking the railroad ties to the dump yourself.

Thank for the suggestions on getting them up & the warnings. I had no idea! We will not offer to dispose of them though. That would require us renting a truck & frankly we don't want the hassle. Getting them up and fixing the holes they leave as well as getting the gravel out of the way is more than enough work. We will move them to the other side of our privacy fence on their property side. The whole situation still irks me that they knew they were in the wrong & made no offer to help remedy the situation. Oh well. Here's to a green lawn & white picket fences!