Conduct Further Research On Means Of Restoring Natural Hydrologic And Sediment Flows And Distributions In The Vicinity Of Roads.

Focus Area

Water Quality/Wetlands


Natural Resources







Research Idea Scope

Because hydrologic conditions around corridors are the result of transportation-system design processes, the major patterns of road hydrology are well documented. It is generally clear, for example, how highway hydrology interacts with the hydrologic system of the landscape, as well as how basic geomorphic processes relate changing hydrology to changing channel form. In addition, the principles of erosion and sediment transport appear to be clear. How highway runoff might be modified to mitigate road–hydrology impacts remains a challenge, however, because that goal can be attained only through a better understanding of the specific effects of changing hydrology on aquatic ecosystems. Thus the effects of varying highway runoff levels on the stability of channels or the functioning of wetlands cannot be predicted. Likewise, the deposition patterns of roadway-generated sediment in streams, rivers, and lakes warrants further study because of the array of ecological effects produced. Although awareness of watershed processes and management has increased in recent years, transportation systems, for the most part, still are evaluated separately from those processes. To build a foundation for mitigating the impacts of transportation systems on watersheds, a better understanding is needed of how road hydrology can be designed to meet the objectives of watershed management programs, which are increasingly focused on maintenance and restoration of environmental quality. Research on water and sediment distributions and flows that link the road corridor to the surrounding land will be key in this regard. Research should also be conducted on the various methodologies for handling and treating highway stormwater quantity and quality to prevent downstream effects.

Urgency and Payoff

Suggested By

FHWA Strategic Plan for Environmental Research 1998-2003

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