mountainous terrain.
1
However, being located at a high elevation does not, in and of
itself, constitute “mountainous terrain,” nor does being located at the foot of a mountain
or where mountains can be viewed. Further, the absolute altitude required to constitute
mountainous terrain will vary in different regions. For example, the altitude of the
Appalachian Mountains is considerably lower than that of the Rocky Mountains, yet the
slope and ruggedness of the terrain in many portions of the Appalachians is mountainous.
Furthermore, roads passing through mountainous terrain are characterized by certain
typical engineering features. For the purposes of determining a CAH’s eligibility for the
15-mile drive standard based on mountainous terrain, the roads on the travel route(s) to
hospitals or other CAHs must meet the following criteria:
• Over 15 miles of the roads on the travel route(s) from the CAH to any hospital or
another CAH must be located in a mountain range, identified as such on any
official maps or other documents prepared for and issued to the public;
and
• Since being located within a mountain range in and of itself does not mean that the
drive to any other hospital or CAH includes travel through “mountainous terrain,” the
roads on the travel route(s) from the CAH to any other hospital or CAH must have
either of the following characteristics:
• Extensive sections of roads with steep grades (i.e., greater than 5 percent),
continuous abrupt and frequent changes in elevation or direction, or any
combination of horizontal and vertical alignment that causes heavy vehicles to
operate at crawl speeds for significant distances or at frequent intervals.
2
(Horizontal alignment refers to the “straightness” of the roadway, vertical
alignment refers to the roadway’s “flatness,” and crawl speed is the speed at
which a truck has no power to accelerate on long, steep grades.
3,4
Thus, roads
in mountainous terrain are commonly described as winding and steep);
or
• Be considered mountainous terrain by the State Transportation or Highway
agency, based on significantly more complicated than usual construction
techniques that were originally required to achieve compatibility between the
road alignment and surrounding rugged terrain. For example, because the
changes in elevation and direction are abrupt in mountainous terrain, roadbeds
may require frequent benching, side hill excavations, and embankment fills.
5
1
United Nations Environment Programme World Conservation Monitoring Centre. (2002). Mountain
Watch. Retrieved August 11, 2010, from http://www.unep-wcmc.org/mountains/mountain_watch/pdfs/.
2
Mannering, F. L., Washburn, S. S., & Kilareski, W. P. (2009). Principles of Highway Engineering and
Traffic Analysis. Hoboken, NJ: John Wiley and Sons, Inc
3
Highway Capacity Manual: 2000 (U. S. Customary Units) by Transportation Research Board (Dec.
2000). p 23-9.
4
Donnell, E. T., Ni, Y., Adolini, M., & Elefteriadou, L. (2001). Speed prediction models on two-lane rural
highways. Transportation Research Record, 1751, 44-55.
5
Mannering, F. L., Washburn, S. S., & Kilareski, W. P. (2009). Principles of Highway Engineering and
Traffic Analysis. Hoboken, NJ: John Wiley and Sons, Inc.