Collision on Highway 400 slows traffic to a crawl CTV NewsHwy. 400 reopens after daylong closure as SIU probes crash involving police vehicle Toronto Star‘Significant problems’: Crash involving OPP vehicle snarls traffic on Highway 400 (update) BarrieToday.com2 seriously injured in crash involving police cruiser on Hwy. 400 in North York CityNews TorontoCrash closes multiple lanes on NB Hwy. 400 at Hwy. 401: OPP CTV News