I ride that trail frequently. Some of the crossings are trickier than others, but I've never had any real issues. As noted by others, you need to take control of the situation when crossing. Certainly, if you have the slightest concern about drivers, even those that appear to be yielding to you, simply wave them on and cross when it's clear of traffic. All the crossings I'm aware of (and I ride from Millwood to Brewster) have stop signs for the trail, meaning traffic on the road has the right-of-way.
IMO, the last thing we need is a bunch of police cruising the trail handing out tickets. In all likelihood, cyclists would be the recipients of the majority of those.