Slow motion crossing gate project

I am automating a pair of Walthers O scale crossing gates that will be installed at a triple track road crossing on my 2-rail layout.  I removed the solenoid actuators and am driving them with a single Tortoise slow motion turnout motor.  (Tortoise bel crank & cable actuators are parts 800-8100 and 800-8101)  Below are photos of the test rig I built to adjust the throws before mounting the gates on the layout.  I'm pleased with the realistic the movement of the gates that the Tortoise provides.    Block occupancy detectors on the approaches to the crossing on each track that will trigger the Tortoise to close or raise the gates.   I'm looking for recommendations for a circuit to flash the lights when the gates are activated.  What flashing circuit do you recommend?