Thanks to Montgomery County's federal legislative delegation, specially earmarked federal funds are being provide specifically to build approximately four miles of sound walls along the Route 309.

Cong. Joseph Hoeffel and former Cong. Jon Fox secured separate infusions of special federal funds from the 1998 Federal Transportation Equity Act for the 21st Century, or TEA-21, and from a federal bill passed and signed into law in October 2000.

Under these bills, the federal government specifically designated $9 million for noise abatement on Route 309 between Limekiln Pike and State Route 63. Pennsylvania will provide $2.25 million in state funds, the required state match.

Normally, sound walls would not be included in a project of this type because PennDOT's program for sound walls— where funds from its regular federal transportation allotment are used— is limited to new highways built on new alignments, or to major highway reconstruction projects that include adding more travel lanes.

PennDOT conducted noise analyses along Route 309 in early 2000 to determine the locations to invest the initial $5 million allocation for sound walls. The locations chosen for walls were along southbound Route 309 between Paper Mill Road and Church Road, and from north of Butler Pike to just south of Norristown Road. Walls will range in height from approximately eight feet to 16 feet.

Then in late 2000, following the receipt of additional earmarked federal funds, PennDOT reviewed its noise modeling data. The department recommended that additional sound walls be placed on southbound Route 309 between Willow Grove Avenue and Waverly Road; on northbound Route 309 between Willow Grove Avenue and Paper Mill Road; and on northbound Route 309 between Church Road and Valley Green Road.

PennDOT soundwall criteria:
Warranted, feasible and reasonable
PennDOT conducted noise measurements along Route 309 to determine the best locations for building sound walls with the limited funds available. Only areas with noise levels of 66 decibels (db) or greater were identified for further consideration for noise abatement.

PennDOT then determined whether or not it would be feasible to build these expensive structures in those high-decibel areas. To be considered feasible, the prospective walls must be able to reduce noise by an average of at least five decibels within the study area. Plus, the walls must be able to be built without affecting driver's sight distance or accessrequirements.

PennDOT then used several criteria to further sharpen the process. To be considered reasonable, proposed sound walls must reduce noise levels by 10 decibels or more at the most impacted sites, and they must be able to do so at a cost of less than $50,000 per affected residential unit. After meeting those tests, the walls must break the line-of-sight between the study area and noise generating traffic, and reduce noise levels to the low 60 decibel range.