MTO (Minister of Transport Ontario) presented to Council an update on the plan to widen Hwy 400, specifically, the stretch between King Road and South Canal Bank Road (north of Hwy 9).  You can see it here.  Key points:  starts June 2015 and the north segment (19 SDRD to north) is being done first; will start more soutern segment as early as 2017; the bridge at Lloydtown Aurora Road is not being moved south.

As the report indicates the traffic will not have access to the additional lanes until the whole segment is widened.  And, initially there will be only 8 lanes (vs current 6) although the work is being done for an eventual 10.