Here in SoCal the MUPS are notorious for all kinds of shenanigans including full scale dune buggies, gas mini-motorcycles and even cars and trucks using the MUPS as private roadways with LACo Public Works keeping open access gates. Once, I was even run off the LART by about 40 mini-motorcycles taking up the entire pavement playing chicken with oncoming cyclists. I gave up on the MUPS for the most part about 5 years ago. Just not worth the risk.