One of the most difficult trail facilities to accomplish is a crossing of an active rail line.
by Stuart Macdonald, Trail Consultant, American Trails
There are many examples of trails crossing railroads at grade in both urban and rural situations. The physical ingredients are signs warning trail users, safety messages, and a surface to allow bike and pedestrian movement while accommodating the rails and flangeways. There are several types of crossing surfaces; see http://safety.fhwa.dot.gov/xings/xing_surfaces.cfm.
Warning signals and even crossing gates to stop trail users when trains are approaching are also in use. Crossing at right angles to the tracks avoids the hazard of bike tires getting caught in the flangeway grooves. The one real danger is where there are two busy tracks to cross. As soon as a train on their side passes, trail users are ready to cross and may not look to see that another train may be approaching on the far track, obscured from view by the first train.
The best answer that you will get for how wide a trail should be is “It depends.”
Survey of skills and competencies to assist in developing a national training strategy for National Scenic and Historic Trails
Categories, lists, and definitions of skills used in trails and greenways work, along with links to classes and resources for training.
The project to complete the Catamount Trail, located in Oregon's Silver Falls State Park, was awarded $145,925.00 in Recreational Trails Funds in the year 2016.