Lecture 27:Environmental Impact

CE 352, Transportation Engineering
Iowa State University
Dr. Souleyrette
Read pages 85 - 88 in the third edition text, Transportation Engineering by Ashford and Wright.

Introduction

The United States is a highly industrialized and mobile nation dependent upon fossil fuels for meeting its growing energy demand. Transportation is a large contributor of pollution to the environment in the form of auto emissions, necessitating the need for government regulations. Agencies such as the Environmental Protection Agency (EPA) and the Department of Transportation (DOT) exist for this reason.

Some important points to remember from the assigned reading are:

• The United States with 5 percent of the world's population uses approximately 30 percent of world's total energy.
• Heavy urban reliance on the automobile and large distances between markets in the US has caused a disproportionate share of the energy to be used by the transport sector.
• The average American travels three times the amount traveled by the average Japanese and nearly twice as much as the average German. In doing so he uses 7.5 and 3.5 times as much energy as his respective Japenase and German counterparts.

Energy

Fossil fuels account for nearly 90 percent of the transportation energy use in the US. The problem with this dependency is that fossil fuels are non-sustainable and negatively impact the environment more than any other energy source. Current government policies are being directed toward improving alternative energy sources. Many private organizations are campaigning to remove hidden biases favoring fossil energy and to include the hidden costs that are often overlooked when comparing its use to alternatives. Some examples of hidden costs are:

• Rises in carbon dioxide levels cause a "greenhouse effect" and lower crop yields.
• Fuel emissions pollute the atmosphere and significantly effect public health in heavily populated areas raising the amount spent on medical care.
• Oil Spills in transport accidents.
• Acid rain which has a severe impact on wildlife and decreases the quality and enjoyment of our natural environment.

Environment

Air Quality

If you would like to see some actual air pollution data in your area, take a look at the Office of Air Quality Planning and Standards website (OAQPS).

The government is trying to level the playing field by removing market barriers in the automobile industry for alternative energy opportunities. New regulations are being implemented by some states to lower fossil fuel emissions by promoting electric vehicle sales in highly populated regions.

Would you like to view the Environmental Protection Agency's pollution regions? (This site has a link for summer job opportunities for students. NOTE: At the EPA site, link to Home, then Offices, Labs and Regions, then Regions and you are there)

Water Quality

If it's in the air, it's in the water. Here's how it happens:

1. Pollutants are emitted by power plants, waste incinerators, factories, pulp and paper mills and automobiles.
2. Wind distributes the pollutants throughout the atmosphere.
3. They contaminate aquifers and waterways in the form of rain, snow and dust.

Emerging Issues in Transportation and Water Quality
University of Texas Researchers Use Artificial Rainfall to Simulate Highway Runoff ... Cool!

Noise Pollution

Noise pollution has many different sources. Some include:

• Automobiles
• Airplanes
• Trains
• Large Machinery
• Crowds of people

Methods of controlling this type of pollution can be quite a task. Some solutions are:

• The construction of noise barriers
• Relocating the source--not realistic in many situations
• Natural vegetation and landscape
• Modifications in the construction of the source
• Noise reduction systems

Noise reduction systems are a new technology that has the capability of reducing soundwaves by 70%. This is done by analyzing the noise output of a source and neutralizing the waves with another source, counteracting each other.

The image above represents how a noise barrier can deflect soundwaves. Only 10% of the noise reaches the home on the other side of the wall. Below are three effective ways of reducing noise.

Want to learn more about noise walls?
Traffic Noise Attenuation as a Function of Ground and Vegetation. Here we have examples of how to use our environment itself as noise barriers.

There are many different companies that have solutions for noise pollution. The Institute of Noise Control Engineering of the USA has many options for many scenarios. If you have a question, they have the answer. (INCE) (More employment opportunities).

Energy Information Administration (EIA).

World Energy Consumption Trends.

Check out the Aviation Noise Abatement Policy.