As for stopping them, "there's not a whole lot [police] can do," Vanore added. Pursuits endanger passers-by and other motorists, and four-wheelers and dirt-bikers can go places police cruisers can't, like the wrong way on streets, on sidewalks or up narrow alleys, he said. That means that cops nab them only when they can successfully sneak up on them in unmarked cars or in tight areas, or when riders stop for fuel or return home.