The closure was between highway 88 and highway 89.
Before noon, the lanes reopened.
Originally the OPP closed both directions of the highway but reopened the northbound lanes, and some time after, the southbound lanes as well.
Police blame black ice and blowing snow for the bad road conditions. The weather has caused traffic congestion and accidents all over the city on Thursday.
See CBC's traffic map of highway 400 here.
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