How to get free parking?

My UMBC friend tries to park at UMD but always has to pay. What’s the best option for free parking. Is it possible to park outside the campus for free then take a nearby bus?

Look for the green areas - free parking weekdays from 4-7p.m. and during day on Sat/Sun. NO free overnight parking http://www.transportation.umd.edu/parking/maps/map_campus.pdf

There is free parking on weekends and holidays at college park metro station (green line). Then catch shuttle bus to campus.