Before a transportation infrastructure investment, such as the construction of a new interchange, can be built, two major processes must occur. First, the project must be planned (e.g., the need for the project is measured, the rough location is established, and some measure of public support is determined) and second, the project must have an environmental review (e.g., examine how the project affects land development, wetlands, air quality, business or residential locations, community cohesion, noise and other physical or social effects). Because of the high cost associated with these two related processes, the Federal Highway Administration (FHWA) has encouraged transportation agencies to pursue Planning and Environment Linkages where the planning process and the environmental process are more tightly integrated in an attempt to reduce duplication of effort. Information about this PEL initiative is available at https://www.environment.fhwa.dot.gov/env_initiatives/PEL.aspx
A knowledge gap in this initiative is that the impact of using information from the planning process to inform the environmental review process is not fully known. As an example, suppose a new roadway is proposed and one is interested in how it will affect noise levels. Typically, as part of the environmental review process, one will generate fairly detailed traffic volume forecasts and then perform a noise analysis. However, it is possible that to reduce costs, one could use the traffic forecasts from the earlier planning process as the basis for the noise analysis. While it is expected that the use of the earlier planning-level traffic forecasts will not be as accurate as the more detailed environmental-level traffic forecasts, the extent to which this difference materially affects the noise analysis is not known.
Accordingly, using a proposed project in Lynchburg Virginia known as the split pairs project, this research effort will examine how the use of planning-level data compares with the use of more detailed environmental level data for the purpose of conducting a noise analysis. We will estimate noise levels near Countryplace lane and Route 221 in Lynchburg using simple spreadsheet equations as well as the more detailed FHWA Traffic Noise model. The input data will come from two sources: planning level documents (notably the 2040 Constrained Long Range Plan for the region) and environmental level documents (a revised traffic analysis being developed as part of the environmental review process). We will compare these noise levels from these four sources to those of noise levels collected in the field. The results of this effort will inform a project being undertaken by the Virginia Transportation Research Council that entails linking the planning and environmental processes. (This project is sponsored by FHWA and the contract monitor had suggested inclusion of planning and environmental linkages.)
This is our expected plan for the period September 1, 2018 - April 30, 2019 with work organized by month. Given 5-10 hours per week, we anticipated 25 hours per month.
September: Learn simple equations for forecasting noise. These equations are given in textbooks we have at VTRC but are also given in the Traffic Noise Model.
October: Learn the traffic noise model (TNM) software (version 2.5).
November: Perform a desktop analysis where you apply both the equations and the TNM software at one location (or more) in the vicinity of the Split Pairs Project near Lynchburg.
December: Visit the site with VTRC staff and collect noise data. This will require learning how to use traffic noise meters which we can borrow from our central office. ;
January: Compare the accuracy of noise levels based on four pieces of information: (1) application of simple noise equations using forecast volumes; (2) application of simple noise equations using detailed volumes; (3) application of TNM using forecast volumes; (4) application of TNM using observed volumes; (5) field measurements.
February - March: Finalize the results in a technical paper that can serve as a stand-alone Appendix for a forthcoming report. The Appendix should be about 10 pages in length, with enough detail that someone can replicate the results.
April: Revise the appendix based on feedback and develop presentations.
Comfort with Excel and mathematical equations is not required but could be helpful. Some theory on how noise is determined could also be helpful. We don't want to overwhelm the student, so do not feel that you have to look at all of this, but if you have a few hours then you might go to the following source titled FHWA Traffic Noise Model (FHWA TNMÂ®) Technical Manual (February 1998) . The URL is here: https://www.fhwa.dot.gov/environment/noise/traffic_noise_model/old_versi.... The manual is long, but please see model 2 Model Description.
Going from very narrow to very broad, we would like for students to be able to (1) understand how to perform a noise analysis both by hand and with computer software, (2) be able to compare results from the field with results from step (1), and (3), gain an appreciation for ways to estimate the social and environmental impacts of transportation systems. Thus this entire project which is focused on noise analysis is really just an example of item (3).