Impacts of Road-Trains on the Geometric Design of Highways

For enhanced efficiency and sustainability, transportation must rely on new technologies. Researchers and engineers work nowadays on many valuable and green transportation ideas. One such idea creates vehicle platoons on freeways to achieve multiple benefits including: reductions in gas consumption, vehicle emissions and traffic congestion through enhanced aerodynamics and better road space utilization; improvements in safety and driver comfort through fail-safe mechanisms; and moderations of collision damages given vehicle speed similarities within platoons. The technological enhancements are built into the vehicles. The existing freeway infrastructures do not necessitate modification. Still, the interactions between the human factors, or lack thereof, and the new technologies may directly impact on the traditional guidelines for freeway design. Over time, the dedicated freeways of the future, whether rehabilitated or built anew, could satisfy guidelines derived specifically for road-trains. Further, freeways built to current guidelines may accommodate travel speeds higher than those originally anticipated per design. It remains to understand 1) why existing freeways can accommodate road-trains, 2) whether design guidelines for road-trains are significantly different from those current, and 3) whether road-train operation results in significant travel design increases. This article seeks to answer these very questions. The investigation of a continuum of transitory to end state scenarios concluded that road-trains promote both shorter required and longer available sight distances, thereby ensuring the adequacy of existing freeways. Road-train operation reduced significantly the minimum lengths requirements, and significantly increased a posteriori design speeds, for vertical curves and drastically less so for horizontal curves.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFB10 Geometric Design. Alternate title: Impacts of Road Trains on Geometric Design of Highways.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Thomas, Natacha Elisabeth
  • 0000-0003-0061-4654
  • Martinez-Perez, Francisco J
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 20p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Design speed; Freeways; Highway curves; Highway design; Sight distance; Traffic platooning
• Subject Areas: Design; Highways; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 01514477
• Record Type: Publication
• Report/Paper Numbers: 14-1027
• Files: TRIS, TRB, ATRI
• Created Date: Feb 18 2014 5:21PM