Impacts of Roads
 

What impacts does a road have on society? On the environment? What are the benefits? What are consequences? In this section, you are given the opportunity to delve more deeply into these questions where there is no “clear-cut” answer.

1.To begin, consider the following picture- of a forestry road network on the east side of Manitoba.

 
   
 

What benefits does this picture illustrate? One might think- increased access to timber supply…or road construction and maintenance employment.

 What impacts of forestry roads does this picture illustrate? One might notice the patchiness of the landscape, or cleared areas along the road side.

Research increasingly indicates that impacts of roads varies according to the type of road, how the road is used, the density of the road network and the tolerance of plant and animal species to impacts such as landscape patchiness or increased hunting access. While there is no definitive answer as to how roads impact the environment, it is becoming increasingly clear that the impact of roads often extends far beyond the edge of the road itself.

2. Consider this image of a new road built on the east side.

 
   
 

What stands out? Possibly the clear straight lines delineating the road demonstrating good craftsmanship.

 Or the buffer along the road where new plant species may take route.

 Possibly the stream passing through a culvert under the road, carrying fish, amphibians, and other organisms.

From an environmental impact perspective, roads are linear features in the landscape that can pose migration challenges to plants and animals. Roads can also provide habitat for new plant species along the sides, and sometimes to invasive plants. Also, road construction can impact water quality, especially if sediments go into the water. All of this depends on the type of road and the conditions of the surrounding environment, as well as care taken during road construction and management.

3. Consider this picture of road construction on the east side.

 
   
 

One may notice that this construction is during the winter time,

considered favorable because of a reduced impact on the environment.  

One may also notice the clearings on either side of the road, and way the road is being constructed.

Forest companies must be accountable to policies and the public when building roads. Rules can include the size of buffers along the road, favorable times and places to construct, and so on. There is also accountability to the public.

Questions for Reflection:  

  1. What has been your experience of the environmental impacts of roads?
  2. What are you thoughts on how the environmental impacts of roads are being addressed by Industry/ Government or others?
  3. What could improve the way environmental impacts are addressed?

Impacts of Roads…A List

The following table provides a list of potential environmental and social impacts of roads. Not all impacts are negative, and some will impact certain areas more than others.

 

Environmental Impacts

Category

Impact

Air quality

  • Dust during construction which can affect plant growth
  • Air emissions from vehicle traffic may impact growth of organisms and quality of habitat in region

Water quality

  • Water runoff carrying sediments, salt and oil from road maintenance, and pollutants from vehicles, makes its way into soil and waterways.
  • Bridges and culverts can harm wetlands and fish habitat, block migration pathways and pollute water.

Soil

  • Soil compaction
  • Increased erosion and sedimentation; altered natural streamflow patterns

Vegetation

  • Invasive species are able to enter new areas more easily, competing with native plant species
  • Logging trucks sometimes transport root disease
  • Removal of original vegetation cover
  • Barrier to dispersal of organisms

Wildlife

  • Disruption of wildlife home range
  • Increased road-kill reduces wildlife populations
  • Increased hunting access (including illegal hunting) also reduces wildlife populations
  • Traffic noise may impact the ability of song birds to reproduce, thereby decreasing population densities

Landscape

  • Habitat is broken into smaller pieces which is harmful to animals that need large, uniterrupted landscapes (like bears)
  • Some species may grow more easily along the edges of roads; some may be pest species
  • Disruption of hydrologic processes
  • Changes in landscape may occur beyond the edge of the road

 

Access

  • Access to mining, hunting, forest harvesting and off-road vehicles increases

Social Impacts

Tourism

  • Loss of tourism opportunities in remote, roadless areas
  • Increased tourism and sport activities in previously inaccessible areas

Noise pollution

  • Noise from traffic and construction

 

The above table was compiled using the following information sources:

 

Lugo , Ariel E. and Gucinski, H. (2000) Function, effects and management of forest roads. Forest Ecology and Management 133 249-262.

 

Saunders, Sari., Mislivets, Mo R., Chen, Jiquan, Cleland, David T. (2002). Effects of roads on landscape structure within nested ecological units of the Northern Great Lakes Region, USA. Biological Conservation 103, 209-225.

Spellerberg, Ian. (1998) Ecological effects of roads and traffic: a literature review. Global Ecology and Biogeography Letters 7, 317-333.

 

Trombulak, Stephen C. and Frissell, Christopher A. (2000) Review of Ecological Effects of Roads on Terrestrial and Aquatic Communities. Conservation Biology. 14, 1 18-30.

More information can be found at the following websites…

  • Wildlands League developed a webtour showing the impacts of unplanned development, and includes a section on road development.

“We have created a series of hypothetical illustrations that illustrate what happens when a series of individual development decisions are taken in a previously intact wild area…”

http://www.wildlandsleague.org/bigwild/conventionaldevelopment.html

On the same Wildlands League website, another list of the impacts of roads is provided. http://www.wildlandsleague.org/roadimpact.html

  • CPAWS - Canadian Parks and Wilderness Society provides a list of how roads damage wilderness.

http://www.cpawsmb.org/take-action/parkwatch-bulletin-jan2004.html 

Quiz questions:  

  1. Name four environmental impacts of roads.
  2. What is the concern around habitat fragmentation?
  3.