Conserving the freeway

I cannot understand this thing. The serria club has sued the city to stop the widening of a freeway. They say it will cause damage to the environment due to air pollution.
Well, air pollution is a big problem here due to the tremendous growth in population we have here. More people=more cars Duh! And the valley has problems with temp inversions that concentrate pollution.
But people have to get where they need to be and driving is, for now, the only way; and traffic here is awful, early and late and really all day, the freeways are clogged with traffic, so building bigger ,wider roads is the only way to relive the congestion. It stands to reason that the faster cars get to where they are going the less time they are on the road and the less pollution they produce. Right?
The serria club see it differently. They contend that more traffic on a road leads to more air pollution. OK. That makes sense. So What! People here can't walk to their jobs. It is a big , spread out city, with three major roads.
I 15 runs north /south along the strip and through North Las Vegas. I 95 the former Oren Gregson expressway( after a mayor) is the major East West route( it goes north and south also in kind of a big S pattern). The 215 loops around the outside of the city but is not completely freeway and mostly serves the south east areas ( Henderson) into the center areas.
The Serria suit has stopped work to widen the 95 which is the route from the hugely grown north west to the rest of the city. It is a big mess that makes no sense. Cars creeping bumper to bumper create a lot more bad air than a free flow of traffic. I wish the serria club would just go Take A Hike.
Adaven