What is road management and why is it important?
Fred Kihara • The Nature Conservancy
The environmental effects of roads include both spatial and temporal dimensions, as well as biotic and abiotic components. These effects may be local (along a road segment) or expansive (related to a large road network).
The spatial effects of roads will vary because species habitat requirements and ecosystems characteristics are diverse and will vary depending on the context. The temporal dimension of road-related effects may occur during road construction or from the subsequent presence, use, and maintenance of road networks. For instance, a few examples of potential effects on soil, water, and aquatic wildlife and habitat may include:
- Displaced and compacted soils resulting in loss of biomass productivity;
- Altered conditions that change soil pH, plant growth, and the vegetative community structure (i.e. light levels and water retention; soil displacement, temperature, and compaction; and dust);
- Reconfigured landforms that can result in changed hydrologic regimes (e.g. altered water table position; interrupted groundwater flow diverted to surface systems; increased water temperatures; changes in the timing of runoff; drained natural wetland habitats; unintentional artificial wetlands; and restricted or altered channels which can result in altered streambed materials); and/or
- Increased number and extent of landslides and debris flow, which can affect terrestrial and aquatic systems.
In the context of Water Funds, mitigation techniques for managing roads typically focus on applying strategic planning (i.e. avoiding vulnerable sites; identifying the most serious problems by assessing road systems at watershed scale; etc.) and undertaking on-the-ground mitigation techniques (site-level actions to reduce erosion, improve culvert and bridge designs; etc.). Other common mitigation techniques include implementing access management and closing and decommissioning roads.