I don't know why people are writing off stinks/toxic/noisy. As someone who has at various times lived near large roadways, this is a huge concern. Car pollution is a really big problem
And we don't even know about all the external effects that gasoline cars have; there was this article in Mother Jones [1] recently that correlated leaded gas to the crime rate, owing to the detrimental effects lead has on the human brain.
[1]: http://www.motherjones.com/environment/2013/01/lead-crime-li...