A method and system for guiding a road construction machine using a machine guidance system comprising at least one each of a machine position sensor, a laser-based sensor, and a processing unit. The machine position sensor first measures a position of a road construction machine relative to a road boundary condition. The laser-based sensor then captures a series of scans corresponding to the boundary condition. The processing unit, using the scans, determines an ideal path of travel for the road construction machine. Based on the ideal travel path, the machine guidance system provides instructions to align the current travel path of the road construction machine to the ideal travel path.