Abstract: A solid state load switching conservation circuit removably connectable with a control output of a traffic control logic circuit and responsive to an actuating input to energize an incandescent lamp from an a.c. power source exhibiting a given voltage level. The switching circuit conserves electrical power consumption and the life span of incandescent lamps and, in this regard, employs a thyristor switch, triac driver, shunting network, voltage level monitoring network, a.c. cycle monitoring network, and processor to provide a soft start form of turn on for the lamps being energized. Subsequent to the completion of soft start control, the conservation approach of the invention then turns to a voltage regulation mode which regulates the voltage applied to the lamp during traffic logic control illumination intervals such that the lamp is energized at an acceptable but lowered RMS voltage to conserve both energy and lamp life spans.