▁T il bury ▁and ▁London ▁was ▁completed ▁two ▁lan es ▁at ▁a ▁time ; ▁the ▁north bound ▁lan es ▁on ▁October ▁ 2 2 , ▁ 1 9 6 3 , ▁the ▁south bound ▁on ▁July ▁ 2 0 , ▁ 1 9 6 5 . ▁The ▁gap ▁between ▁Mary sv ille ▁and ▁King ston ▁was ▁opened ▁by ▁ 1 9 6 2 . ▁The ▁final ▁sections , ▁from ▁west ▁of ▁Corn wall ▁to ▁Lanc aster , ▁were ▁opened ▁between ▁ 1 9 6 2 ▁and ▁ 1 9 6 4 ; ▁two ▁lan es ▁opened ▁to ▁Lanc aster ▁on ▁September ▁ 1 1 , ▁ 1 9 6 2 , ▁but ▁the ▁other ▁two ▁were ▁not ▁completed ▁until ▁July ▁ 3 1 , ▁ 1 9 6 4 . ▁The ▁last ▁segment , ▁to ▁the ▁Ontario – Que bec ▁border , ▁was ▁opened ▁on ▁November ▁ 1 0 , ▁ 1 9 6 4 . ▁Finally , ▁on ▁October ▁ 1 1 , ▁ 1 9 6 8 , ▁the ▁Th ous and ▁Islands ▁B yp ass ▁opened . ▁This ▁final ▁piece ▁was ▁comm emor ated ▁with ▁a ▁pla que ▁to ▁sign ify ▁the ▁completion ▁of ▁Highway   4 0 1 . ▁ ▁In ▁Toronto , ▁engine ers ▁and ▁survey ors ▁were ▁exam ining ▁the ▁four - lane ▁by pass , ▁while ▁pl ann ers ▁set ▁about ▁design ing ▁a ▁way ▁to ▁handle ▁the ▁comm uter ▁highway . ▁In ▁ 1 9 6 3 , ▁transport ation ▁minister ▁Charles ▁Mac N aught