Which amenities would you most like to see more of along rail-trails? (You may check all that apply.)

In remote areas (poor cell phone coverage) call boxes might be appropriate. At entry points, post telephone numbers for police, medical emergency, taxi service, and repair shop.
At appropriate points, signs indicating restaurants nearby.
better lighting in tunnels

I have hiked nearly 10,000 miles on rail grades...including many not listed in your data...few trails have camping facilities.

Greetings from Vermont. I have recently become a member. I appreciate the work that you do in making former railroads into recreational trails. I have been on one such trail in central Ohio. Mount Vernon. Here in Vermont, where I live, there is an abandoned railroad along the Lamoiile River. There has been talk of making it into a trail, accessable to walkers,hikers,and bicycles. ATVs or 4 wheelers should not be allowed on such a trail! They create erosion, and make noise disrupting the natural beauty of a place.

I think pioneer more camp sights would be wonderful. This would allow for more self-contained trips on longer trails.

When I plan a multi-day trip I need to know where I'm going to sleep (B&B or motel) and where I will eat. Hopefully both will be available close to the trail every 40 t0 50 miles.

It's great to make use of old rails and turn them in to something very useful and scenic instead of an old railroad dump site full of litter and other various abandoned and neglected places you try your best to avoid.