Go to many trucking websites and the horror stories about modern engine maintenance costs and failures on the road have increased as these new technology engines are introduced. It might be wise to let the technology mature and become reliable before we damand more from it. Also the regulators need to change the formulas from pollution grams per mile to pollution grams per kilogram of fuel burned. One of the enormous mistakes in automobile pollution standards was to use pollution per mile traveled instead of using pollution per kilogram of fuel burned.

About time.

I'm quite surprised and pleased that Trump and the EPA are even allowing this. I also regularly need to close my outside air vents while driving.Over 20% from transportation? That is ENORMOUS. These emissions are literally killing people.

Another "cash for clunkers"?

I was behind a smallish truck the other day. I had to close the air vents to block out the dense, black smoke it was spewing.

First we should ask how much it will cost to implement the "improvements" the EPA is talking about. Things that will cut the pollution from trucks in city traffic may increase operating costs with will mean increased charges for hauling the goods on which we depend.

For example the drag-reducing under trailer and tail fins that California requires are only effective at 60+mph, but California requires them despite their speed limit of 55.

If they really want to reduce the truck's contribution to city air pollution maybe routes around the congestion would help more.

Semis and other big trucks have always been "low-hanging fruit" as far as reducing NOX and other emissions (large amount of emissions from a relatively small number of vehicles). It's just that they've been relatively untouched previously because of lobbyist/big business/etc. "connections". I'm hoping this new initiative isn't just a lot of smoke, so to speak...