( ( -LRB- ( NUI -RRB- ) ) ( - ( ( ( Air quality ) ( inside ( cars ( on ( most roads ) ) ) ) ) ( ( ( ( is ( worse ( than ( the ( outside air ) ) ) ) ) , ) ( according ( to ( recent studies ) ) ) ) . ) ) ) )
(ROOT (S (PRN (-LRB- -LRB-) (NP (NNP NUI)) (-RRB- -RRB-)) (: -) (NP (NP (NNP Air) (NN quality)) (PP (IN inside) (NP (NP (NNS cars)) (PP (IN on) (NP (JJS most) (NNS roads)))))) (VP (VBZ is) (ADJP (ADJP (JJR worse)) (PP (IN than) (NP (DT the) (JJ outside) (NN air)))) (, ,) (PP (VBG according) (PP (TO to) (NP (JJ recent) (NNS studies))))) (. .)))
(NUI) - Air quality inside cars on most roads is worse than the outside air, according to recent studies.
(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))))) (. .)))