▁the ▁Cab in ▁John ▁Bridge , ▁ ▁is ▁a ▁bridge ▁carrying ▁Inter state ▁ 4 9 5 ▁( Cap ital ▁B elt way ) ▁across ▁the ▁Pot om ac ▁River ▁between ▁Mont gom ery ▁County , ▁Maryland ▁and ▁Fair f ax ▁County , ▁Virginia ▁in ▁the ▁United ▁States . ▁It ▁is ▁an ▁American ▁Water ▁Land mark . ▁ ▁The ▁bridge ▁has ▁five ▁traffic ▁lan es ▁in ▁each ▁direction . ▁The ▁outer most ▁l ane ▁in ▁each ▁direction ▁is ▁an ▁entrance / exit - only ▁l ane ▁for ▁traffic ▁to / from ▁the ▁Clara ▁Bart on ▁Park way ▁in ▁Maryland ▁and ▁the ▁George ▁Washington ▁Memorial ▁Park way ▁and ▁Ge or get own ▁Pi ke ▁( State ▁Route   1 9 3 ) ▁in ▁Virginia . ▁There ▁are ▁no ▁facilities ▁for ▁ped est ri ans ▁or ▁cycl ists , ▁which ▁are ▁prohib ited . ▁ ▁History ▁ ▁Open ed ▁on ▁December ▁ 3 1 , ▁ 1 9 6 2 , ▁the ▁bridge ▁was ▁originally ▁named ▁the ▁" C ab in ▁John ▁Bridge " ▁because ▁of ▁its ▁proxim ity ▁to ▁the ▁community ▁of ▁Cab in ▁John ▁on ▁the ▁Maryland ▁side ▁of ▁the ▁Pot om ac ▁River . ▁The ▁bridge ▁opened ▁without ▁a ▁ceremony ▁due ▁to ▁the ▁cold ▁weather . ▁On ▁May ▁ 3 0 , ▁ 1 9 6 9 , ▁the ▁bridge ▁was ▁officially ▁renamed ▁the ▁" American ▁Leg ion ▁Memorial ▁Bridge " ▁in ▁a ▁ceremony ▁led ▁by ▁L t . ▁Gen . ▁Lewis ▁B . ▁H ers he y , ▁director ▁of ▁the