The list includes all road users such as drivers, passengers, pedestrians, motorcyclists and cyclists. It distinguishes pedestrians, bicyclists/motorcyclists, small cars, and larger SUVs/trucks. A biker bar is a bar that is frequented by motorcyclists (bikers). Outlaw motorcycle clubs reflect their social roots and the demographics of motorcyclists in general. His research led to the use of crash helmets by both military and civilian motorcyclists. Helmets also play a major role in the safety of motorcyclists. Lien and many of the motorcyclists stopped their vehicles. In December 1909, eleven drivers and a few motorcyclists returned for speed trials. He accused 38% of motorcyclists of evading vehicle excise duty. Some are owned or managed by people who are friendly toward motorcyclists. Old Summer Road remains one of the great challenges for adventuring motorcyclists and 4WDers. "The Weight" played while the protagonists, hippie motorcyclists, enjoyed a ride through Monument Valley. The Old Summer Road has become a challenge for adventure motorcyclists. Kingsbury Grade (highway 207) is another popular route with local motorcyclists. Two AFVs retreated, while the majority of the motorcyclists were taken prisoner.