aska ▁Highway , ▁the ▁principal ▁route ▁out ▁of ▁the ▁state ▁through ▁Canada . ▁The ▁state ▁capital , ▁June au , ▁is ▁not ▁accessible ▁by ▁road , ▁which ▁has ▁sp ur red ▁several ▁deb ates ▁over ▁the ▁dec ades ▁about ▁moving ▁the ▁capital ▁to ▁a ▁city ▁on ▁the ▁road ▁system . ▁One ▁unique ▁feature ▁of ▁the ▁road ▁system ▁is ▁the ▁Anton ▁Anderson ▁Memorial ▁T unnel , ▁which ▁links ▁the ▁S ew ard ▁Highway ▁south ▁of ▁An ch orage ▁with ▁the ▁relatively ▁isolated ▁community ▁of ▁Wh itt ier . ▁The ▁tunnel ▁held ▁the ▁title ▁of ▁the ▁longest ▁road ▁tunnel ▁in ▁North ▁America ▁( at ▁nearly ▁ 2 . 5 ▁miles ▁[ 4   km ]) ▁until ▁completion ▁of ▁the ▁ 3 . 5 ▁mile ▁( 5 . 6   km ) ▁Inter state ▁ 9 3 ▁tunnel ▁as ▁part ▁of ▁the ▁" Big ▁Dig " ▁project ▁in ▁Boston , ▁Massachusetts . ▁The ▁tunnel ▁retain s ▁the ▁title ▁of ▁the ▁longest ▁combination ▁road ▁and ▁rail ▁tunnel ▁in ▁North ▁America . ▁ ▁State ▁high ways ▁ ▁Other ▁roads ▁Top ▁of ▁the ▁World ▁Highway ▁ ▁Br id ges ▁and ▁t unn els ▁ ▁Anton ▁Anderson ▁Memorial ▁T unnel ▁ ▁Mill ion ▁D ollar ▁Bridge ▁ ▁K nik ▁Arm ▁Cross ing ▁( pro posed ) ▁ ▁Gra v ina ▁Island ▁Bridge ▁( pro posed ) ▁ ▁Ber ing ▁Stra it ▁bridge ▁( pro posed ) ▁ ▁Rail ▁and ▁bus ▁travel ▁ ▁The ▁Al aska ▁Rail road ▁runs ▁from ▁S ew ard ▁through ▁An ch orage , ▁Den ali ,