Sound Barriers
October 2023 Update
NH DOT anticipates starting construction on the I-95 Pannaway Manor sound barrier in April 2024. Geotechnical and environmental permitting is underway and anticipates securing 60% plans the first week of November, 85% plans at beginning of February 2024 and final plans in mid-March. NH DOT plans another public meeting, date TBD.
Results of the noise study conducted at New Franklin School (.pdf).
Given that the New Franklin School site does not meet the federal criteria for sound barriers, can the City build the barriers instead?
The state will not allow the City to build on state property adjacent to the highway due to regulations that prohibit the City from funding a project another community could not afford and placing it on state land if it does not meet the federal requirements for a sound barrier, which this site does not.
Could the City build sound barriers on City-owned land?
Since New Franklin School sits below the grade of the highway and the barriers would need to extend above the roadway, the walls would be significantly higher than other sound barriers. For example, if the school playground is 20 feet below the highway grade, and a 20-foot wall is needed to mitigate the noise, this would mean a 40-foot wall would be needed.
In addition to the height concern, sound barriers must break the line of sight between the source and the receiver and, ideally, they are placed close to one or the other. Constructing sound barriers on City-owned land would place them far from the highway, significantly reducing their effectiveness, compared to conventional highway barriers constructed at the edge of the roadway. Furthermore, due to the finite length of the school property, highway noise would still find its way around the end of any barrier built on City-owned property.
A barrier would not be beneficial at this site.
January 2023 Update
Pannaway/I-95: NH DOT has this project listed (see below) although the schedule has shifted to Fall 2023 not June 2023.
New Franklin: The City has contracted sound monitoring in the New Franklin School area during Feb 2023 School Vacation Week.
At a City Council presentation on November 15, 2021, (timestamp 43:56) NHDOT officials confirmed that the Pannaway Manor and Rockingham Avenue neighborhoods met the criteria for the construction of a sound barrier between homes there and nearby Interstate 95. However, a proposed sound barrier for the New Franklin School neighborhood — which is located close to I-95, Route 1 and the Spaulding Turnpike — did not meet the NHDOT criteria.
Assistant DOT Commissioner Bill Cass told the City Council the projects qualified for state monies because of the upcoming project that will allow the use of I-95 shoulders from about the Portsmouth traffic circle to the Maine/New Hampshire border during peak volume periods, primarily summer weekends, starting in 2023. Because that project is adding capacity to the highway, the sound barrier projects qualify for funding.
The City sent a letter to NHDOT in September 2022 suggesting supplemental funding for sound-proofing to enhance the privacy fencing DOT plans to install along the I-95 corridor adjacent to New Franklin School. In December 2022 the City received this letter from DOT explaining why Federal projects disallowed that approach.
Background
Residents in the Pannaway Manor neighborhood requested sound barriers along the Interstate 95 corridor to reduce noise coming from I-95. In July 2019, NH DOT declared Portsmouth eligible for $2.3 million in state funding for the construction of the sound barriers. At the time, Portsmouth was the first community in the Granite State to be approved for New Hampshire Department of Transportation's Type II Noise Abatement Program.
Noise abatement for the I-95 corridor was listed in the city's CIP in 2018. In April of that year, Department of Transportation Assistant Commissioner Bill Cass visited and inspected the site where the sound barriers would be installed, and the following January, the City Council adopted the Noise Highway Overlay District. Council members also adopted zoning ordinances addressing development in areas that are close to the highway, which were required for the state funding application. In fall 2019, NHDOT conducted a pilot assessment of the project to identify all Type II-eligible abatement measures within the City of Portsmouth.
In September 2021, The Governor’s Advisory Commission on Intermodal Transportation heard public comment on including the sound barriers in the draft 2023-2032 Ten-Year Transportation Improvement Plan. In addition to Pannaway Manor, residents of the New Franklin/Jewels neighborhood spoke in favor of sound barriers for their neighborhood.
City funding for additional sound barriers is being considered for the CIP for FY24-29.
