Highway Capacity Manual Chapter on alternative Intersections and Interchanges

Today’s transportation professionals, with limited resources available to them, are challenged to meet the mobility needs of an increasing population. At many highway junctions, congestion continues to worsen, and drivers, pedestrians, and bicyclists experience increasing delays and heightened exposure to risk. Today’s traffic volumes and travel demands often lead to safety problems that are too complex for conventional intersection and interchange designs to properly handle. Consequently, more engineers are considering various innovative treatments as they seek solutions to these complex problems. Highway Capacity Manual (HCM) Chapter 23, Ramp Terminals and Alternative Intersections, provides qualitative guidance and computational analysis procedures for four interchange designs and three intersection designs.(1) The original three interchange designs (i.e., the partial cloverleaf (parclo), diamond, and singlepoint urban interchange (SPUI)) are considered conventional designs. The four new alternative designs are the diverging diamond interchange (DDI, also known as the double crossover diamond interchange), displaced left-turn (DLT) intersection, restricted crossing U-turn (RCUT) intersection, and median Uturn (MUT) intersection. These designs offer substantial advantages over conventional at-grade intersections and grade-separated interchanges. The FHWA Alternative Intersection and Interchange Report (AIIR) provides information on each alternative treatment covering salient geometric design features, operational and safety issues, access management, costs, construction sequencing, environmental benefits, and applicability. This TechBrief summarizes information on HCM Chapter 23, specifically with regard to the new intersection and interchange designs.

• Record URL:
  https://www.fhwa.dot.gov/publications/research/operations/16069/16069.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/38218
• Corporate Authors:

  Federal Highway Administration

  Saxton Transportation Operations Laboratory
  McLean, VA  United States 
• Authors:
  • Hale, David
• Publication Date: 2016-7

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: 4p
• Serial:
  • TechBrief
  • Publisher: Federal Highway Administration
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Design; Highway safety; Intersections; Restricted crossing U turn intersections
• Identifier Terms: Displaced left-turn intersection; Diverging diamond interchange; Highway Capacity Manual; Median U-turn intersection
• Subject Areas: Design; Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01646341
• Record Type: Publication
• Report/Paper Numbers: FHWA-HRT-16-069, HRDO-20/07-16(200)E
• Contract Numbers: DTFH61-12-D-00020-T-13002
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: Sep 22 2017 4:45PM