"More than 45 million people live, work, or attend school within 300 feet of a major transportation facility in the United States alone ... These facilities include heavily traveled highways that can cause adverse noise effects. ... In addition to annoyance and speech interference, recent studies have reported on links between highway traffic noise and health effects. The (WHO) reported on environmental health effects, including heart disease, sleep disturbance, and cognitive impairment in children. WHO states, “... at least one million healthy life years are lost every year from traffic-related noise in the western part of Europe” (WHO, 2011). These human health issues as well as the effects of highway traffic noise on wildlife are a growing concern. To help minimize the effects of highway traffic noise, researchers and practitioners must understand the noise sources, how the sound propagates to nearby communities, and how to reduce noise levels at the source, during propagation, or at the receiver. Further challenges lie in establishing and implementing highway traffic noise policies."