New Noise Barrier Products & Noise Barrier Approval Research & Guidelines

Focus Area



Community & Cultural Concerns, Environmental Process




Under $99,000


Under 1 year

Research Idea Scope

TERI Administrator Note (January 2009): Funded as NCHRP Project 25-25, Task 40. Completed January 2008.

The cost and total quantity of noise barriers as an environmental abatement measure have increased substantially in the past decade. Since the Federal Noise Regulation was promulgated in 1970, there have been over 2,200 miles of noise barriers built at a cost of 3.4 billion dollars (in 2004 dollars) using Federal-aid funds. Noise barriers can be made from many material types, such as concrete, block, brick, wood, metal, and plastics. The number of viable materials has increased substantially over the past 36 years. A survey of existing noise barriers to address issues such as maintenance, construction, or other environmental problems would be beneficial to the State Departments of Transportation (SDOTs). Guidance for selecting material types and noise barrier manufacturers could eliminate costly problems that may arise in the future.
Currently each SDOT approves noise barrier manufacturers based on their own specific requirements. There are many sampling and testing requirements (such as noise reductions for difference frequencies, structural strength, shatter resistance, flame spread, toxicity, anti-graffiti evaluations, clear zone characteristics etc.) for State approval. The requirements are not the same for each State and vary depending on material type. Noise barrier manufacturers and several States without noise barriers have requested that the Federal Highway Administration (FHWA) standardize and provide recommended approval approval processes for the States. The FHWA noise program has always promoted flexibility for the SDOTs to design their noise programs based on cost, public desire, and other environmental considerations. A survey of the SDOT’s testing and sampling requirements would assist the SDOTs and noise barrier manufacturers with the approval process.
Research Objectives:
A Survey whose results provide a description of currently available noise barrier material properties and identification of unit cost ranges. Of the materials, identify noise barrier products already approved in one or more State Departments’ of Transportation and products pending approval.
Some states are just starting with noise wall construction in their states, others are grappling with the need for durable, safe, cost effective, and aesthetically pleasing light weight materials to place on bridges, retrofit locations, and other sensitive areas. With the increasing need for capacity of state roadways and the increasing cost for materials, states need a tool to evaluate and select cost effective techniques to reduce noise and stay within financial constraints. This survey of noise barrier materials and recommended methods is meant to help states to achieve these goals.
Funding this effort would provide immediate benefit to multiple states.
Since crash testing is a large cost for noise barrier material testing and acceptance, identify alternative crash testing procedures or equivalent calculations to reduce costs but still provide safe materials within the clear zone of roadways.
Specific Tasks:
Proposed study tasks include:
To maintain state flexibility, but provide additional background recommendations for state staff, states need recommendations for new noise barrier product approval criteria which may include:
·         summarize how states in the US and other countries currently evaluate new noise barrier products for noise, material properties, structures, maintenance, and context sensitive design
.      Identify best practices/recommendations for new noise barrier product evaluation and approval

Suggested By

Mia Waters; Washington State Department of Transportation Mariano Berrios; Florida Department of Transportation

[email protected], [email protected]