Distance to nearest road in the conterminous United States

The USGS Geographic Analysis and Monitoring (GAM) program has developed a national, high resolution dataset that gives the distance to the nearest road every 30 meters across the conterminous 48 states.  This work provides the first unified national picture of roadless space, vehicular accessibility, and intensity of road construction.  

The new dataset is the first member of the National Overview Road Metrics (NORM) family of road related indicators.  This indicator measures straight-line or Euclidean distance (ED) to the nearest road, and is given the compound name NORM ED.  NORM ED data can be viewed and downloaded from the transportation section of the web viewer for The National Map, http://nationalmap.usgs.gov.  The full-resolution dataset for the conterminous states is made of 8.7 billion values.