 These machines allowed the mechanisation of the snow clearing process, reducing the labor required for snow removal and increasing the speed and efficiency of the process.The expansion of the aviation industry also acted as a catalyst for the development of winter service vehicles during the early 20th century.Even a light dusting of snow or ice could cause an aeroplane to crash, so airports erected snow fences around airfields to prevent snowdrifts, and began to maintain fleets of vehicles to clear runways in heavy weather.