Warning lights on channelizing devices
New York uses warning lights only on drums at spot hazards. Lights are not used on a longitudinal series of drums because of the potential for the lights penetrating the windshield of an impacting vehicle, and NYDOT feels the reflective area of the drum usually provides adequate night visibility. In addition, a series of flashing lights can confuse the driver. NYDOT does, however, place warning lights on the first two channelizers (whether drums or barricades) in a lane closure taper at night. Lights are generally not used on barricades in a longitudinal series. If they do, the batteries must be on the ground rather than on the face rail of the barricade. Lights are a maintenance headache.
NYDOT does use high-intensity flashing warning lights on some warning signs when emphasis is needed–typically on interstates. In those cases, designers would specify the lights in the traffic control plans.