Below are several examples of Type II programs in three States and a comprehensive review of Type II programs prepared for Texas DOT. Several other States have Type II programs that may provide examples of priority ranking systems. Those below provide a sampling of different approaches to developing a priority system.
Performed a statewide noise study and identified locations where noise levels exceed 78 dBA in the loudest hour. These fifty-three locations make up the Type II priority list. For more information, go to http://www.mhd.state.ma.us/default.asp?pgid=content/barriers01&sid=about.
Uses a calculation called the Noise Abatement Priority Index (NAPI) to rank neighborhoods where 90% of development predates the adjacent highway. The index scores various factors such as highway volume, age of the development, and housing density within 400' of the highway and ranks the neighborhoods statewide. For additional information, please refer to ODOT's Standard Procedure for Analysis and Abatement of Highway Traffic Noise (February 2010).
Performed a statewide evaluation to identify locations eligible for consideration as Type II projects and identified 21 locations for the Type II project list. For more information, see http://www.adc40.org/presentations/summer2005/05_Bowlby%20TRB%202005%20TDOT%20Type%20II%20Program.pdf.
The Texas Department of Transportation offers a comprehensive review of Type II programs in the Study of Statewide Type II Noise Abatement Program for the Texas Department of Transportation (February 2000). This document evaluates the Type II programs implemented by other State highway agencies and provides a good overview into the decision-making processes involved in establishing a Type II program. This document is available at: http://www.utexas.edu/research/ctr/pdf_reports/1754_1.pdf.