( ( ( The improvement ) ( in ( ( ( air quality ) and ) ( road safety ) ) ) ) ( ( ( are apparent ) already ) . ) )
(ROOT (S (NP (NP (DT The) (NN improvement)) (PP (IN in) (NP (NP (NN air) (NN quality)) (CC and) (NP (NN road) (NN safety))))) (VP (VBP are) (ADJP (JJ apparent)) (ADVP (RB already))) (. .)))
The improvement in air quality and road safety are apparent already.
(ROOT (S (S (VP (VBG Limiting) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NP (NNS cars)) (PP (IN on) (NP (DT the) (NNS roads)))))))) (VP (MD would) (ADVP (RBS most) (RB likely)) (VP (VB improve) (NP (DT the) (NN air) (NN quality)) (PP (IN in) (NP (JJ large) (NNS texas) (NNS cities))))) (. .)))