After significant winter snowfalls, Tioga Pass was buried in snowdrifts from 15 to 50 feet deep over several miles by April 2019. Caltrans Maintenance must open this pass before summer. This is a very hazardous task, with State Route (SR) 120 right next to a steep drop-off. Maintenance workers have very little visual indications for the road location when the snow is this deep. The MPRO system uses GPS and an in-vehicle display, along with a highly accurate base map, to show the vehicle operator where they are currently at relative to the road.