The Maryland State Highway Administration's sound barrier guidelines provide for the evaluation of sound barriers for communities adversely impacted by noise from state maintained highways. Sound barriers are evaluated in two separate categories: Type I and Type II.
General eligibility criteria
General eligibility criteria apply to both types of sound barriers:
- Noise levels equal or exceed 66 decibels.
- Construction of a sound barrier would reduce noise levels by seven to 10 decibels at the most severely affected homes.
- Cost of the sound barrier does not exceed $50,000 per home. At least 75 percent of the homeowners that would benefit affected are in favor of a barrier.
Sound barriers for new construction
A sound barrier for new construction, or reconstruction, of a state highway. A community may be eligible for this type of sound barrier if it first meets the General Eligibility Criteria and the following Type I criteria:
- The majority of the impacted homes existed prior to the date of approval of the proposed highway improvements.
- The existing noise levels are projected to increase by 10 decibels.
- The noise levels from the planned highway improvements will result in an increase of noise levels by three decibels or more.
Sound barriers for existing highways
A sound barrier along existing highways. A community may be eligible for this type of sound barrier if it first meets the General Eligibility Criteria and the following Type II criteria.
- A majority of the impacted homes existed prior to the highway.
- The county has enacted local noise controls, consistent with state requirements, for future development adjacent to state highways.
- The local jurisdiction agrees to fund 20 percent of the project and money is available.
- The right of way needed for the construction or permanent location of a sound barrier is donated.
When a sound barrier is not the answer
Sound barriers do have limitations. To work effectively, the barrier must be high enough and long enough to block the view of the road. Homes on a hillside overlooking a road; buildings higher than barriers; homes scattered too far apart and openings in noise barriers for driveway connections or intersecting streets are not good areas for sound barriers. In some cases, SHA can offer alternatives to help reduce noise levels.
To receive a copy of the Sound Barrier Policy please call the
Office of Environmental Design (OED) at 410-545-8640