Back in the 1970’s, Denver started to become known for its poor air quality so they began implementing new measures in order to reduce pollution.For more than 200 days a year, Denver’s air quality index was over the federal air quality standards in most categories. In order to get rid of their nicknamed sky, “the brown cloud,” the Denver region, along with the state of Colorado, led the nation in some very strict resolutions. The Denver region banned wood burning fireplaces in newly built homes, switched to a liquid deicer instead of putting sand on the roads and changed their power source from coal to natural gas, which is more expensive. Colorado started an auto-emissions testing program and began adding oxygenates to their gas to reduce carbon monoxide emissions in the wintertime.
In 2002, Denver met federal air quality standards for the first time in 30 years due to a combination of their strict adherence of the Clean Air Act of 1990, their unique resolutions to meet goals and cleaner cars. The Denver Regional Council of Government continues to make sure that Denver is excelling at improving air quality by making sure the transportation plan and improvement program are conforming to the air quality implementation plan within the Denver Transportation Management Area. They mitigate for additional pollution by implementing transportation control measures.
Rail transit in the Denver region is the most significant control measure that has been implemented starting in 1979. The first segment opened in 1994 with many extensions and expansions since then, including the emerging FasTracks project. Other projects that are being funded to improve air quality are bike/pedestrian projects, local bus service projects, traffic signal upgrades, operation projects and capacity projects.