id ▁Rail ▁Transport ation ▁Study ▁and ▁which ▁recommended ▁a ▁ 4 ▁Ph ase ▁plan ▁including ▁a ▁pro tot yp ical ▁D art ▁Under ground : ▁▁ ▁Ph ase ▁ 1 ▁- ▁Up grade ▁and ▁elect r ify ▁How th ▁– ▁B ray ▁( comple ted ▁ 1 9 8 4 ▁as ▁the ▁D ART ). ▁ ▁Ph ase ▁ 2 ▁- ▁An ▁under ground ▁line ▁from ▁Con n olly ▁to ▁He ust on . ▁Rap id ▁Trans it ▁tracks ▁He ust on ▁to ▁Cl ond alk in ▁over ground . ▁Sp ur ▁to ▁T all ag ht ▁from ▁Cl ond alk in ▁( a ▁small ▁part ▁was ▁completed ▁in ▁ 2 0 1 0 ▁when ▁Rap id ▁Trans it ▁tracks ▁were ▁installed ▁either ▁side ▁of ▁Cl ond alk in ). ▁ ▁Ph ase ▁ 3 ▁- ▁A ▁short ▁nor ther ly ▁sp ur ▁off ▁the ▁May no oth ▁line ▁to ▁Bl anch ard st own ▁and ▁a ▁short ▁sou ther ly ▁sp ur ▁to ▁Broad stone . ▁( The ▁former ▁was ▁never ▁completed ▁but ▁was ▁partly ▁rev ived ▁in ▁ 2 0 0 1 ▁as ▁Metro ▁West ▁before ▁that ▁was ▁itself ▁sh el ved ▁in ▁ 2 0 1 1 ▁and ▁the ▁latter ▁sp ur ▁was ▁opened ▁as ▁Lu as ▁Cross ▁City ▁in ▁December ▁ 2 0 1 7 ). ▁ ▁Ph ase ▁ 4 ▁- ▁A ▁tunnel ▁from ▁Broad stone ▁to ▁Sand ym ount . ▁( This ▁was ▁later ▁red es igned ▁as ▁Metro ▁North ▁from ▁Dr um cond ra ▁to ▁St