A ground marking apparatus is configured to apply marking material to a ground surface. The ground marking apparatus includes a beam supported by a beam mount and extending along a beam axis. A carriage is disposed on the beam and movable on the beam along the beam axis. A carriage motor operably interfaces with the beam and is configured to move the carriage along the beam. A dispense arm is supported by the carriage and is configured to move relative to the beam as the carriage moves along the beam.