A USDOT University Transportation Center

Increase in Covered Miles of Roadway or Covered Surface Area

An increase in covered miles of roadway is a measurable indicator that measures the progress of stormwater management programs. It is an indication that there is a reduction in stormwater runoff. The indicator reveals that measures have been implemented to increase the number of roads and parking lots and pave over natural areas such as gardens and lawns since paved surfaces prevent rainwater from seeping into the ground, reducing the runoff that occurs during storms.1

This indicator helps determine the effectiveness of the following objectives

  • Less Contamination
  • Less Emissions
  • Less Traffic Noise
  • Connectivity and Inclusion
  • Healthy Destinations
  • Less Traffic Violence
  • Active Transportation
  • Green Space

Data Collection

The EPA collects and stores data on covered miles of roadway. The EPA uses a variety of methods to collect this data, including aerial surveys, ground-based measurements, and satellite imagery.2

Examples

Protecting Water Quality From Water Runoff

Some researchers have found that increasing the pavement surface area can increase stormwater runoff. A team of researchers at the U.S Environmental Protection Agency conducted a study to determine if increasing the surface area of roadways could successfully reduce stormwater runoff. From the findings of the study, the researchers found that increasing the pavement surface area by even a small amount (1 to 2 per cent) can reduce stormwater runoff by up to 10 per cent. However, other studies have not seen such clear results.

https://www3.epa.gov/npdes/pubs/nps_urban-facts_final.pdf

1. Dirt Connections. 5 best ways to reduce stormwater runoff [Internet]. Dirt Connections. 2020 [cited 2022 Aug 8]. Available from: https://www.dirtconnections.com/5-best-ways-to-reduce-stormwater-runoff/
2. Weatherly, J.N., Derenne, A. Comparing rates of probability discounting using paper-pencil or online versions of the fill-in-the-blank or multiple-choice methods of data collection. Psychol Rec [Internet]. 2014 [cited 2022 Aug 17];64(2):271–86. Available from: https://www.epa.gov/measurements-modeling/collection-methods