▁the ▁Co ent unnel , ▁crossing ▁the ▁No ord ze ek ana al ▁(" N orth ▁Sea ▁Canal "). ▁This ▁tw in ▁t ube ▁tunnel ▁is ▁not orious ▁for ▁traffic ▁j ams ▁for ▁dec ades ▁and ▁so ▁another ▁two ▁tub es ▁have ▁been ▁built . ▁These ▁new ▁tub es ▁opened ▁on ▁ 1 3 ▁May ▁ 2 0 1 3 ▁and ▁the ▁old ▁tub es ▁were ▁closed ▁for ▁extensive ▁renov ation . ▁On ▁ 2 1 ▁July ▁ 2 0 1 4 ▁the ▁old ▁tub es ▁were ▁re open ed ▁after ▁comple ting ▁the ▁renov ations ▁and ▁all ▁four ▁tub es ▁became ▁be ▁available ▁for ▁traffic . ▁ ▁The ▁city ▁of ▁Amsterdam ▁has ▁a ▁network ▁of ▁number ed ▁st ads routes ▁( city ▁routes ). ▁These ▁routes ▁are ▁indicated ▁with ▁an ▁" s " ▁prefix ▁followed ▁by ▁a ▁three ▁digit ▁number ▁starting ▁at ▁ 1 0 0 . ▁Since ▁these ▁s - routes ▁are ▁connected ▁to ▁the ▁A 1 0 ▁motor way ▁and ▁each ▁s - route ▁only ▁cross es ▁the ▁motor way ▁once , ▁these ▁numbers ▁can ▁be ▁considered ▁as ▁the ▁first ▁exit ▁numbers ▁on ▁Dutch ▁motor ways . ▁Rec ently , ▁regular ▁exit ▁number ing ▁has ▁been ▁implemented ▁based ▁on ▁the ▁numbers ▁of ▁the ▁s - routes . ▁For ▁example , ▁the ▁j unction ▁leading ▁towards ▁the ▁s 1 0 6 ▁used ▁to ▁be ▁exit ▁number ▁s 1 0 6 ▁and ▁is ▁now ▁number ed ▁as ▁exit ▁ 6 . ▁ ▁History ▁Const ruction ▁started ▁in ▁ 1 9 6 2