“We bought a house/land 6 years ago and signed an ingress/egress easement with the previous owners to allow them the use of our driveway to access their property that adjoins ours. Since that time they have moved in 2 mobile homes on their property and are renting them out. One is now being used as a daycare for children. We are having major problems with the renters (& parents of the daycare children) speeding up and down our driveway and forcing us to get out of their way when we are on it. We offered to help pay for a new driveway on their property to allow them access to the highway, they have refused our offer. In an effort to slow down the traffic we have put up a nonlocking gate at the end of the driveway where it joins their property. The property owners are now saying we have no legal right to install the gate.”
The answer to your question is that you must look at the document you signed to see what it includes, and what it doesn’t.
If I had to guess, I would suspect that the document is silent on this point. As a general rule, however, when you have an ingress/egress easement across your property, you can continue to use your property in any way which doesn’t unreasonably interfere with the ingress/egress rights of the person who has the easement.
I would certainly argue, if I were your attorney, that a non-locking gate doesn’t interfere with their access to their property. In fact, even a locking gate would arguably be okay, assuming you provided them with keys. But this is a fact question, and they could argue the other side of it.
A more significant argument on your part might be that you agreed to allow access for one family and the traffic that it generates, so having two families on the property exceeds the scope of your easement grant. If that argument were successful, you could significantly restrict the usefulness of the easement to the current residents, but probably at the cost of having them pretty unhappy with you.
In any case, I would suggest that you try consulting with a local attorney, to see if perhaps the spectre of possible legal entanglement will make them more amenable to discussion.