Don't build a layout without at least two rerailers
You're going to need at least 2 of these rerailers on any layout. You will need one on the siding where you stage your locos and cars. Another should be placed somewhere on the run to take care of minor derailments. Just before an incline is a very good location for a rerailer. The Atlas rerailer comes with embossed wood grain to simulate a wooden RR crossing; however, you can use joint compound or several thick coats of paint to change them to concrete. Use them wherever you have RR crossings. Hint: don't put them under overpasses and keep any crossbucks far enough away that you can use them to replace rolling stock without damaging the corssbucks.