Why is the street sweeper operator only sweeping streets in fron

West Wildwood - Why is the street sweeper operator only sweeping streets in front of certain homes and skipping past others? I noticed that after the sweeper passed my home the driver went out into the center of the street and bypassed my neighbor and the house next to my neighbor. Then the sweeper went back into the curb and continued to sweep the gutters. This didn't happen once, it happened again about two weeks later when the street sweeper returned. There were no vehicles in the street blocking my neighbors' street. What's up?