This paper describes the development of preliminary designs for the auxiliary facilities for a two-lane roadway in mountainous terrain, including truck-climbing lanes, chain up/off areas, slow-vehicle turnouts, and brake check areas. Initial designs suggested the need for an additional lane (a truck-climbing lane) for nearly the entire 35.4 km (22 miles) of the project, an impractical and costly solution. Since this was not feasible, a corridor approach was used that evaluated the Highway Capacity Manual and Washington State Department of Transportation Design Manual procedures. A graphical solution developed warrants by plotting stationing, grades, profiles, bridges, speeds, levels of service, and other key features in each direction. The goal was to provide safe operations throughout the entire alignment. Considering the auxiliary features as an integrated unit allowed the designers to relate each feature to the other and plan the siting of multiple-use facilities. (A) For the covering abstract see IRRD 873033.


  • English

Media Info

  • Features: References;
  • Pagination: p. 129-38

Subject/Index Terms

Filing Info

  • Accession Number: 00712379
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 90-5410-343-4
  • Files: ITRD
  • Created Date: Oct 24 1995 12:00AM