You can use Atlas Insulated Rail Joiners item # 6093. To create an insulated rail section you will need 2 insulated rail joiners as shown on the attached drawing. Replace the standard Nickel Silver rail joiners at the ends as shown. Then attach a wire to any of the Nickel Silver rail joiners inside the area between the 2 Insulated joiners as shown. This wire will provide detection required to set the flasher in operation.