Legal Question in Real Estate Law in Washington

To answer this question, you need to look at the conveyance in your deed that grants the right of way (easement) for others to traverse the property. That said, there is nothing to stop you from putting up the signs, but enforcing the speed is another matter all together. Speed bumps and gates are also something that we'd have to look at your deed to begin to answer.

Still, to play this out, let's say the deed is silent on this issue. If I were you, I would get in touch with the folks who use the easement and explain to them that you are concerned about the speeds at which they traverse your property for the various reasons that the high speed concerns you, i.e., excessive noise, safety issues, etc.

Tell them that you want to install speed bumps as a passive restraint on speed and get their input. Either they are going to agree, or it will inevitably turn hostile and likely lead to court. So, when you do this, I highly suggest you consult counsel along the way so that as you take each step, you want to make sure that they have as little ammunition as possible in court. You'll also want to make sure that you have whatever permits are necessary to install the speed bumps, if in fact any are needed.