UniChris

I somewhat agree, in a way before they started having personal utility (essentially all of my non-trivial rides are rail trails) I was even opposed to the rail-trail concept. But keeping unused rights-of-way intact is hard, notice how a lot of rail-trails end up with detours around assorted squatters like state highways, junkyards, nurseries, etc.

One idea that has some promise is rail-with-a-trail. For example, the Maybrook line circumferentially connecting two (in a way, three) of Metro North's spokes that radiate from NYC is a two track ROW that long ago degraded to a single track, and even that might need some work to be passable to anything but a hi-rail pickup. They last used it a few years back when a washout on a main line stranded some passenger equipment, to move it over to another line and still be able to make use of it on other routes.

The plan now is to build a trail on the portion of the ROW that no longer has rails, with a nominal fence inbetween. A six mile piece going the wrong direction from existing trail and remaining rail service connections was done a few years back, but now there's Empire State Trail money allocated to Metro North to have the railroad itself hire and supervise a contractor to build the trail on the remaining 30-odd miles that will (with a mile long road gap) connect two existing trails, ultimately creating a 96 or so mile route from NYC to Poughkeepsie and across the river almost to New Paltz.

Rail of course isn't the only "other use" - something they did a number of years back was run fiber optic lines along the Maybrook (just as many railroads have with all of their ROWs). And I if I'm remember correctly I saw a lot of fiber dig warning signs along portions of the Farmington Canal trail, too (and actually a rail trail as the canal only lasted a few years before a railroad was built in its place)