As the world is increasing in population, the sound from traffic is a significant issue. The U. S. Department of Transportation recognizes that noise from highways is a large issue, particularly for those who live close to the highway. Engineers have come up with several solutions to the problem. One solution is noise barriers which can be dirt mounds between a highway and homes or high vertical walls. A second solution is planting vegetation such as trees. Select one of the two options and answer the following: 1. Identify the wave interaction involved in your chosen solution. (i. E. Refraction, reflection, diffraction) 2. Explain how the interaction would reduce noise for the homeowners. 3. Identify how the interaction would affect noise for the highway