Roundabouts have long been popular in Europe, where pedestrians have traditionally been given priority over cars. But many American cities remain skeptical. Maybe that’s because the word roundabout still evokes visions of car-choked traffic circles, the kind that South Jersey was once famous for, where motorists jockeyed for position as they inched toward an outlet. Sidewalks and crosswalks, if they existed at all, were an afterthought, since pedestrians rarely figured into the equation.