There is significant traffic congestion on freeways during peak hours in metropolitan areas across the country that lead to increased emissions and other impacts. Both recurring bottlenecks and nonrecurring events…
Transportation agencies conduct a significant portion of archaeological investigations in the US and in many developed countries around the world. Once a transportation project is built, however, there remains the…
Background Roadway lighting has been shown to measurably reduce nighttime fatal and other crashes. However, roadway lighting can negatively impact insects and animals through attraction and disorientation or by disrupting…
Background Currently, there is minimal guidance from federal agencies on how to conduct noise and vibration analyses specific to wildlife, which results in differing approaches to noise analyses that may…
FY2022 NCHRP PROBLEM STATEMENT OUTLINE 1. Problem Title Concrete Curing pH Level Impacts for Minimization of Harm to Aquatic Species 2. Background Construction and maintenance actions regularly require state Department…
During project development and construction, DOT agencies must assess the liability of real property acquisitions of contaminated property as well as contaminated waste management generated by disturbing these areas during…
Recent research findings identified 6PPD-quinone as the major agent responsible for exceptionally high levels of rapid mortality of adult Coho salmon in some urban streams. Lethal effects occurred in Coho…
As the U.S. Environmental Protection Agency (EPA)’s preferred air dispersion model for refined transportation project analyses, AERMOD is used to model roadway “link” source using AREA, VOLUME, LINE, RLINE, or…
The Section 4(f) Net Benefit Programmatic Evaluation was created in 2005. It provides a streamlined opportunity for Section 4(f) compliance when compared to completing an Individual Section 4(f) Evaluation. The…
Background Per- and polyfluoroalkyl substances (PFAS) are a group of manmade fluorinated chemicals that have been manufactured and used in a variety of industries since the 1940’s. They are persistent…