Cars on the road today are 99% cleaner than they were in 1970. Air quality in the United States is much, much better as a ...

A reworded version of Leno's Law is being proposed in California, in the hope of ensuring classic cars do not need smog ...

California built its reputation as a clean-air pioneer not through voluntary action by automakers but through a legal mechanism most Americans have never heard of: a federal waiver that lets one state ...

Collectible cars due for registration renewals starting April 30 no longer will have to pass Arizona emission tests. A law passed by the Legislature last year and recently approved by the ...