The western end of the O&Q currently forms the CPR mainline from Detroit and Windsor to Toronto, running through North Toronto and into the CPR Toronto Yard in Agincourt. The route eastward remains in limited use through Peterborough and on to Havelock where it serves several mines and quarries. However, most of the traffic between Toronto and Perth was redirected to a new CPR line running along the shoreline of Lake Ontario, the Campbellford, Lake Ontario and Western Railway. This turns northeast at Kingston to meet the O&Q at Perth, where the original O&Q forms the rest of the CPR mainline to Montreal.