Walls of fame: states share successful strategies for partnering with the public to design aesthetically pleasing noise barriers

Public Roads, May-June, 2003 by John J. Sullivan, IV

Lizards, cacti, ladybugs, trees, leaves, animal tracks, and mountain scenes. No, this is not a list of topics in a textbook on ecology. Rather, these items are design elements adorning highway barriers constructed to decrease noise from traffic.

In the past, transportation agencies focused on ensuring that barriers reduce noise, but in recent years designers have given increased attention to the aesthetic qualities of these walls--and for good reason. According to Bob Armstrong, leader of the Noise Team in the Federal Highway Administration's (FHWA) Office of Natural and Human Environment, aesthetics are just as important--maybe even more important-than the noise reduction capacity of a barrier. "Many citizens," Armstrong says, "view an ugly barrier as a waste of time and money and are likely to say that it doesn't reduce noise."

The most successful highway noise bafflers complement their surroundings, while performing their intended acoustical functions. The baffler's size, shape, materials, texture, treatments, and context all contribute to how the wall looks to motorists and community members alike.

Across the country; designers are involving the public in making decisions about the look and feel of existing and new barriers. Whether jagged, stepped, sloped, uniform, irregular, colored, plain, straight, curved, or textured, today's most aesthetically successful barriers reflect the local flavor of their communities and enhance the quality of the transportation environment.

Reducing Noise

Noise, defined as unwanted or excessive sound, is an undesirable byproduct of modern life. Although noise emanates from many different sources, noise from highway traffic is among the most pervasive and difficult to avoid.

Traffic noise has been a Federal, State, and local concern since the 1960s, and the first noise barrier was built in 1963 in Washington State. In 1976, FHWA developed the first Highway Noise Barrier Design Handbook to help State highway agencies address all the considerations in noise barrier design appropriately. In the two decades since FHWA published the handbook, substantial advancements have occurred in all elements of barrier design. Further, increased community and motorist interest has fueled the push to provide less expensive and more aesthetically pleasing and environmentally friendly barrier designs.

With highway construction projects often located near existing residential and commercial environments, barriers are by far the most common technique for reducing the impacts of traffic noise. In 2000, FHWA's Noise Team gathered information from State departments of transportation (DOTs) to assess the extent of noise barrier construction. The team concluded that, as of 1998, 44 State DOTs and the Commonwealth of Puerto Rico had constructed more than 2,610 kilometers (1,620 miles) of barriers at a cost of more than $1.9 billion (in 1998 dollars).

The survey also revealed that most barriers are constructed from concrete or masonry block, although other building materials include wood, metal, earth berms, brick, recycled materials (such as plastics and composite polymers), or combinations of these materials. In general, barrier dimensions range from 3 to 5 meters (10 to 16 feet) in height, and the average cost ranges from $175 to $200 per square meter ($16- 19 per square foot). To see more results from FHWA's survey, "Summary of Noise Barriers Constructed by December 31, 1998," visit ww.fhwa.dot.gov/envkonment/bar98txt.pdf.

Most roads and streets (97 percent) in the United States fall under the jurisdiction of State and local governments. Federal jurisdiction is limited mainly to national parks, national forests, and other government-owned lands. According to FI-IWA noise regulations, each State DOT has the flexibility to determine the need for noise abatement on streets and highways--and its feasibility--and to balance the benefits of abatement measures with the social, economic, and environmental costs. Federal noise regulations--found in Title 23 of the U.S. Code of Federal Regulations, Part 772, "Procedures for Abatement of Highway Traffic Noise and Construction Noise"--apply to projects where a State DOT requests Federal funding for participation in the improvements.

According to Armstrong, advance planning and shared decisionmaking are the best ways to ensure that a noise barrier meets the needs of the community, the motoring public, and the transportation agency. Armstrong emphasizes the need to think consciously about aesthetics during project planning, with input from a multidisciplinary team, including landscape architects, noise engineers, and the community.

"An ugly barrier isn't going to sell," Armstrong says. "You can spend a lot of money, but if you put up a barrier people don't like, you're going to have a problem. States can gain public acceptance for noise barriers by getting community buy-in--and sometimes communities even volunteer to contribute money for special aesthetic treatments. They often see public involvement as a plus because they have a say in what is going into their backyards."