▁Highway   2 ▁along ▁the ▁shore ▁of ▁the ▁Saint ▁Lawrence ▁River ▁within ▁the ▁Saint ▁Lawrence ▁Valley . ▁N ortheast ▁of ▁Bro ck ville ▁is ▁the ▁inter change ▁with ▁Highway   4 1 6 , ▁which ▁heads ▁north ▁to ▁Ott awa . ▁At ▁the ▁Ontario – Que bec ▁border , ▁Highway   4 0 1 ▁becomes ▁Autor oute   2 0 ▁and ▁continues ▁to ▁Montreal . ▁ ▁Tra ffic ▁volume ▁The ▁M TO ▁publish es ▁year ly ▁traffic ▁volume ▁data ▁for ▁provincial ▁high ways , ▁expressed ▁as ▁an ▁average ▁daily ▁vehicle ▁count ▁over ▁the ▁span ▁of ▁a ▁year ▁( A AD T ). ▁The ▁table ▁below ▁comp ares ▁the ▁A AD T ▁at ▁several ▁locations ▁along ▁Highway   4 0 1 ▁using ▁data ▁from ▁ 1 9 6 9 , ▁ 1 9 8 8 , ▁ 2 0 0 8 ▁and ▁ 2 0 1 6 . ▁ ▁History ▁ ▁Pre de cess ors ▁▁ ▁Highway   4 0 1 ' s ▁history ▁pred ates ▁its ▁design ation ▁by ▁over ▁two ▁dec ades . ▁As ▁autom obile ▁use ▁in ▁southern ▁Ontario ▁grew ▁in ▁the ▁early ▁ 2 0 th ▁century , ▁road ▁design ▁and ▁construction ▁advanced ▁significantly . ▁Following ▁frequent ▁er os ion ▁of ▁Lake ▁Sh ore ▁Road , ▁then ▁mac ad am ized , ▁a ▁concrete ▁road ▁known ▁as ▁the ▁Toronto – H amilton ▁Highway ▁was ▁proposed ▁in ▁January ▁ 1 9 1 4 . ▁Const ruction ▁began ▁on ▁November ▁ 8 ▁of ▁that ▁year , ▁following ▁the ▁on set ▁of ▁World