The invention discloses a traffic signal lamp for roads. The traffic signal lamp comprises a base, a substrate, a top plate, a power supply device, a signal lamp, a lifting threaded rod, a motor, an axle base and a limiting plate; the base is of a hollow structure, the motor is fixedly installed inside the base, the lower side of the substrate is fixedly connected with the base, the top end of thesubstrate is fixedly connected with one side of the top plate, the upper portion of one side of the substrate is fixedly connected with the axle base through a connecting rod, the lower portion of one side of the substrate is connected with one side of the limiting plate, a through hole is formed in the limiting plate, one end of the lifting threaded rod is rotationally connected with the axle base, the other end of the lifting threaded rod is connected with a coupler, the output end of the motor penetrates through the base to be connected with the coupler, a straight thread sleeve is fixedlyconnected to the back face of the signal lamp through a fixing rod, and the straight thread sleeve is cooperatively connected with the lifting thread rod. Due to the cooperative effect of the liftingthread rod and the straight thread sleeve, the height of the traffic signal lamp can be changed, the traffic signal lamp is convenient to overhaul, and by arranging the solar power supply device, theeffect of saving energy is achieved.