In this NASA Tech Briefs' "Meet Our Readers" Q&A, we feature Ken Polcak, Noise Abatement Design & Analysis Team Leader for the Maryland State Highway Administration.
Polcak is a civil engineer by training and acoustical/noise control engineer by practice. He deals with transportation noise analysis and mitigation. Polcak's experience centers on the acoustical design of noise barriers, computer prediction and modeling of propagation, field testing and research, and impact assessment.
What are common workplace scenarios and challenges that you frequently encounter as an acoustical/noise control engineer? Can you take us through an example?
Much of my work is quality assurance/quality control in nature, in that I review technical analyses and provide guidance on interpretation of policy and application of criteria. Some of the biggest challenges center on reconciling evolving practices and state-specific policies with past studies, to ensure consistency and continuity over time.
The best example is the recent Federal Highway Administration (FHWA) noise regulation revisions, which became effective in mid-July 2011. Our last 12-month period has focused on developing and revising existing policy to conform to the revised regulation. All the while, there are ongoing studies and analyses, which must be considered in light of the new regulations and grandfathering considerations, all coordinated with FHWA.
What kinds of regulations is the Federal Highway Administration calling for, and how does that affect what you’re building?
There have been different details that have changed over the years, but this most recent revision to the regulation was issued last July. It sets out the general guidelines for criteria, that each of the states then establish for themselves. You have to have your own official written policy that governs the issue of highway noise in your particular state. It’s called the Procedures for the Abatement of Highway Traffic Noise and Construction.
What kinds of noise barrier developments are we talking about here? What are the end results of what you’re building?
There are two elements to the regulation. One is more of a mandate; it’s centered on the National Environmental Protection Act (NEPA) and all the requirements of doing assessments of environmental impacts. Whenever there is a federally funded project, you need to determine your existing noise levels, your future levels, and then determine if you have impacts. If you do have impacts, you have to consider mitigation of some form. Generally, the abatement of choice is the noise barrier, which is basically just a big vertical wall in between your highway and the adjacent sensitive area.
In general, whenever we identify that there’s a community or some other sensitive areas like churches, schools, or parks, we look to build these noise barriers. We have about 105 miles worth of barrier in the state of Maryland that have been built so far.