Air pollution has become a significant problem in the US as well as the world over years. It’s the result of variety of sources like industrial, agriculture, mechanical and transportation. Sadly, transportation which releases a great amount of carbon dioxides, nitrogen oxides and other toxicity is proven the leading cause of air pollution. There are several transportation factors that contribute to air pollution in the US.
The first factor is the excessive use of SUVs and cars. Vehicle has played an important role in the US because of its use of connecting people to anyplace. As “America's population of automobiles & drivers are increasing” (Davis), it’s true that every households has the average of 2 or 3 cars in their garage. It means most of people have their own car. In developed country like US, there is high level of activities that requires people to move around a lot. They like to use cars as their favorite transportation even if it just takes 5 minutes to go to Wal-Mart or grocery, then cars become necessary in their life. Whenever cars are turned on, they pollute. The author of “Car, Pollution and Environment” lets us know that cars harm the air by releasing “30 percent of the carbon dioxide” from “the combustion system” (“Car, Pollution and Environment”). Then, just imagine millions cars are running on the way everyday to see how much it affects our environment. In addition, with their bigger size, weight and guzzling engine, SUVs are more likely to burn more gas than cars do. For example, one article reported that “a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. […] A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide over the same distance of 500 city miles (Ecobridge)”.
One aspect of this factor is the “persistence of old and outdated technology” in the SUVs and cars’ fleet (Gorham). In a family, higher-income members tend to get a new cars and leave it for lower-income ones. Therefore, the old cars are still on our road until its usefulness has expired. So it’s a problem that people have recognized since older cars pollute more than new ones do. As the same size and model, older vehicles are more likely inefficient than new ones as they use the obsolete technology which wastes a lot of gas and produces carbon dioxide (Car Heaven). Commonly vehicle’ age is 10 years-old or higher (Gorham). As their ages are getting higher, they are more losing their efficiency. For example, “A 14 year old vehicle produces 19 times more smog-forming emissions than a 2004 or newer model (Car Heaven)”.
The second factor is the permissive regulation on truck emissions. Sean, a senior editor at American city & County’s sister publication, said that diesel trucks have been a pollution emitter over years. “While they make up only 2 percent of vehicles in...