TOWARD A COMMUNITY IMPACT MEASURE FOR ASSESSMENT OF TRANSPORTATION NOISE

Despite improvements in techniques for measuring and predicting transportation noise, no one has yet developed a reliable method for identifying the total impact on a community of the noise generated by a proposed transportation facility. A procedure, the noise annoyance impact, is developed for measuring this total impact in a variety of units. In essence, the noise annoyance impact transforms noise measurements for a particular location into a number representing the average impact of such noise on people, multiplies this number by the number of people in that location, and sums this result over the full extent of the area. A sample application, based on two proposed highway alignments for an urban area, used the traffic noise index and the noise pollution level to represent the noise and the data from an earlier survey by the Building Research Station in England to specify the percentage of the population annoyed at a particular reading of a traffic noise index or noise pollution level. The resulting noise annoyance impact was thus expressed as the total number of people annoyed. The noise impact is easy to interpret and, therefore, provides a measure of the total areal impact of noise that can be used effectively in public participation efforts. In addition, the formulation of the noise annoyance impact is mathematically sound. It permits combination of all of the pertinent noise data for the full study area into a single number. Although further research is necessary to specify more accurately the relationship between noise and the percentage of population annoyed or any other measure of average noise impact, the principles of the noise annoyance impact can be applied now.