Greater Manchester Group of Road Safety Officers In 2005 12,805 road users were injured on the roads of Greater Manchester. Of these...9112 were drivers and passengers - 2144 were pedestrians - 769 were on a pedal cycle and 780 were motor cycle riders and pillions. So what are the main causes of these collisions? Human error plays a part in 95% of all collisions. If you look at the main causes it is the DRIVER that has the greatest influence in preventing these collisions. For more information regarding the changes to the seatbelt legislation, visit the cars page. Top of the Page.