machine including a powered truck - like vehicle having a support base at the rear end and an apparatus for cutting a drive - in passage across a concrete curbstone , a sidewalk or the like . the apparatus is mounted on the base and essentially comprises two spaced parallel booms mounted at one end on the base and an elongated bridge structure extending between and perpendicularly to the booms , being connected to them and provided with a drive so that it can be displaced along the booms with respect to the support base of the vehicle . the booms and bridge structure are pivoted from an inoperative position where the bridge structure is above the support base to an operative position where the booms and bridge structure are swung outwardly of the support base in a position for cutting the curbstone , sidewalk or the like . a carrier , having a concrete rotary cutting saw , is mounted on the bridge structure and displaceable in a first direction along one face of the structure , the saw itself being displaceable along a second direction which is perpendicular to the first mentioned direction . in this manner , with the apparatus in the operative position , the rotary saw is first advanced in the second direction through the curbstone , sidewalk or the like and then in the first direction to cut an elongated slot determining the elongated extent of the drive - in passage .