1. A roadway cleaning apparatus in combination with a prime mover comprising a vehicle chassis having an engine control means thereon including a control cab and having a hydraulic fluid pump, the improvement comprising: conveyor means transversely connected to the forward end of said chassis, said conveyor means including a substantially cylindrical housing disposed horizontally adjacent the surface of the earth, said housing having closed ends and having a coextensive downwardly and forwardly directed opening, said housing having a rearward and upwardly directed discharge opening medially its ends, a pair of cooperating coaxially aligned screw conveyors extending between and journalled by said housing ends, and impeller blades interposed between and connected, respectively, with adjacent ends of said screw conveyors medially the ends of said housing, the length of each said impeller blade being equal with the radius of said screw conveyors, said screw conveyors being characterized by a helical edge portion generating a cylindrical plane coinciding with a circular plane generated by the outwardly diRected limit of said thrower blades as the conveyors are rotated about their axis, said helical edge portions and said impeller blades having a series of spaced-apart slots transversely formed therein adjacent their outer edge; a plurality of brush segments each having a rectangular base portion and bristles secured thereto; means extending through the slots and securing said brush segments, in base end to end abutting relation to the respective said screw conveyor and impeller blade outer edge portions; drive means for rotating said screw conveyors; belt and pulley drive means extending between and respectively connected with said prime mover and one end portion of one said screw conveyor; a rectangular fluid containing closed tank having a material receiving opening in its top wall and having inner and outer spaced-apart walls having heat and cold insulation therebetween mounted on said vehicle chassis rearwardly of and projecting above the horizontal plane defining the upper limit of said control cab; a pair of shafts transversely journalled in coaxial aligned relation by the forward end portion of said chassis; a pair of arms pivotally connected at one end portion, respectively, to the respective outwardly disposed end portion of the respective said shaft, the other end portion of said arms being pivotally connected, respectively, with opposing end portions of said housing; a pair of braces projecting forwardly of said tank in laterally spaced relation above said housing; a pair of pressure operated cylinders extending between and connected, respectively, with the forward end portion of said braces and opposing end portions of said housing for vertical pivoting movement of said housing about the horizontal axis of said shafts; a discharge tube connected, at one end, with said housing around its discharge opening and extending rearwardly and upward, at its other end, and connected with said tank top wall around the receiving opening; a heater mounted on said chassis; piping connected with said heater and extending, intermediate its ends into said tank and being helically wound, adjacent the inner periphery of said tank; and, an antifreeze liquid filling said heater and said tubing.