Bicycling and walking facilities provide a wide range of benefits to individuals, their communities, and the surrounding environment. The information below summarizes some of the many types of environmental benefits that can be gained by accommodating pedestrians and bicyclists within North Carolina's transportation network.
Sidewalks, bike lanes, paths, and greenway trails help to reduce vehicle emissions, fuel consumption, and congestion.
Reduction in Vehicle Emissions & Fuel Consumption
Providing safe accommodations for walking and bicycling can help to reduce automobile dependency, which in turn leads to a reduction in vehicle emissions - a benefit for North Carolinians and the surrounding environment. As of 2003, percent of U.S. greenhouse gas emissions are attributed to the transportation sector, and personal vehicles account for almost two-thirds (62 percent) of all transportation emissions(1). Primary emissions that pose potential health and environmental risks are carbon dioxide, carbon monoxide, volatile organic compounds, (VOCs), nitrous oxides (NOx), and benzene. Children and senior citizens are particularly sensitive to the harmful affects of air pollution, as are individuals with heart or other respiratory illnesses. Increased health risks such as asthma and heart problems are associated with vehicle emissions(2).
Decreasing the dependency on daily motor vehicle trips and increasing the availability of alternative travel methods such as walking and bicycling can reduce emissions and assist in improving air quality. Replacing two miles of driving each day with walking or bicycling will, in one year, prevent 730 pounds of carbon dioxide from entering the atmosphere(3). Other studies have likewise shown air quality benefits as a result of increased walking and bicycling rates and reduced vehicle miles traveled:
- As of 2008, roughly 9.5% of all U.S. trips are made by walking or bicycling. A modest increase in walking and bicycling to 13% of all trips would save 3.8 billion gallons of gasoline each year and reduce CO2 emissions by 33 million tons. A substantial increase in walk and bike rates to 25% of all trips would save 10.3 billion gallons of gasoline and prevent 91 million tons of CO2 emissions.(4)
- Minneapolis-St. Paul, MN: If bicycles were used for half of the short trips made on good weather days, the Twin Cities could prevent 300 deaths and save $57 million in annual medical costs due to reduced air pollution and increased physical activity. Collectively, 11 major Midwest cities would save $7 billion in medical costs each year and prevent 1,100 deaths.(5)
- A 5% increase in the walkability of a neighborhood is associated with a per capita 32.1% increase in active travel, 6.5% fewer miles driven, 5.6% fewer grams of nitrous oxides (NOx) emitted, and 5.5% fewer grams of volatile organic compounds (VOCs) emitted.(6)
By providing balanced transportation choices, citizens of North Carolina will also have a sense of contributing to the solution of reducing air and noise emissions.
Energy Conservation and Independence
According to the National Association of Realtors and Transportation for America, 89% of Americans believe that transportation investments should support the goal of reducing energy use(7). The transportation sector currently accounts for 71% of all U.S. petroleum use, with 40% of daily trips made within two miles or less and 28% less than a mile(8). Providing alternative modes of travel has the potential to reduce dependency on foreign oil and promote more energy-efficient transportation choices in communities. Most of the short trips made in the U.S. and in North Carolina are single-occupancy vehicle trips that could be made on foot or by bike with improved facilities.
The benefits of fully accommodating pedestrians and bicyclists and increased rates of walking and bicycling are diverse and substantial. While increased safety for pedestrians and bicyclists is the most apparent benefit to many, facilities that allow for safe walking and bicycling reduce the collision risk for all users and contribute valuable health, economic, mobility, and environmental stewardship benefits to North Carolinians and to our state.
Improved Water Quality and Wildlife Habitat Pedestrian and bicycle trails are often included as part of greenway corridors, offering transportation options while also contributing to environmental quality. Greenways help link fragmented tracts of land to provide larger habitats for wildlife while also protecting sensitive natural features, natural processes, and ecological integrity. These tracts of open space also contribute to cleaner air by preserving stands of plants that create oxygen and filter air pollutants such as ozone, sulfur dioxide, carbon monoxide and airborne particles of heavy metal. Vegetation within the greenways also creates a buffer to protect streams, rivers and lakes, preventing soil erosion and filtering pollution caused by agricultural and roadway runoff. Trails that are built within greenway corridors give pedestrians, bicyclists, and other non-motorized trail users access to these natural areas and provide safe off-road facilities for walking and bicycling. Greenways also provide opportunities for restoring wildlife habitat in areas that have been previously disturbed. Invasive, exotic species are often a threat and greenway maintenance is essential to remove these species.1) Office of Transportation and Air Quality, Environmental Protection Agency. (2006). Greenhouse Gas Emissions from the U.S. Transportation Sector: 1990-2003. Report number EPA 420 R 06 003 2) Health Effects Institute (2010). Traffic-Related Air Pollution: A Critical Review of the Literature on Emissions, Exposure, and Health Effects. Special Report 17. 3) Federal Highway Administration. (1992). Benefits of bicycling and walking to health. 4) Gotchi, T. & Mills, K. (2008). Active transportation for America. Railsto-Trails Conservancy. 5) Grabow, M.L., Spak, S.N., Holloway, T., Stone, B., Mednick, A.C., & Patz, J.A. (2011). Air quality and exercise-related health benefits from reduced car travel in the Midwestern United States. Environmental Health Persepectives, 120(1): 68-76. 6) Frank, L.D., Sallis, J.F., Conway, T.L., Chapman, J.E., Saelens, B.E., and Bachman, W. (2006). Many Pathways from Land Use to Health: Associations between Neighborhood Walkability and Active Transportation, Body Mass Index, and Air Quality. Journal of the American Planning Association 72(1): 75-87. 7) National Association of Realtors and Transportation for America. (2009). 2009 Growth and Transportation Survey. 8) Bureau of Transportation Statistics. (2010). Transportation Statistics Annual Report 2010.