I have just installed some streets & roads using scrap pieces of linoleum. First I will get the dimentions that I need and measure it out on the back of the linoleum. If you are not sure how it will fit just set a larger piece over the area that you want to cover and then put your structures on top and mark the edges. When I paint the back of the linoleum I spray paint it with a dark gray and then a light over spray of a tan or earth color. I used yellow & white pinstrip tape for cars cut down the middle for the lines on streets and roads (you could mask and paint with your air brush). The thickness is just right to fit between rails as well as being very plyable to follow contours. Try it as it is not messy either.
have to say this is a first, never thought of using linoleum
you can try bondo .detemine the width you want then build up the outside edges with layers of tape then mix your bondo and spread with a 2 to 3 inch putty knife.use a flat piece of wood or a piece of glass about 10 buy 10 to mix your bondo on if u use glass sand the edges so you dont cut your self anything flat and smooth works for mixing i also use card board to mix on beacuse its disposable i also used spackle once for a short section but it takes a while to dry it also cracks after awhile justl like real roads do.if u use bondo for crossings be sure to keep it clear of the tracks make spacer between the bondo and tracks use a lil wax paper agianst the bondo to keep it from stickig to your spacer. bondo is sandable and paintable good luck …and remember its a jungle out there …a hobo jungle that is… tramptrac