I have a 35 foot by 8 foot layout, where there are double Lionel Postwar crossing gates (a total of 4) in the vicinity of 2 reverse loops in one place on the layout, triggered by insulated rails. See photo below:
These crossing gates, which powered from the transformer through an Atlas Connector, are very reliable and durable, having worked flawlessly for 25 years. Fixed voltage is set at 18 volts. Arnold