A Discussion on the Current MUTCD Standards on Traffic Control Signals for Freeway Entrance Ramps

Standards are specified for the placement of signal heads for traffic control signals at freeway entrance ramps, or ramp meters in Section 41.02 of the newly published Manual on Uniform Traffic Control Devices). For simultaneous operations, for example when ramp control signals are operated such that green signal indications are always display simultaneously to all of the lanes on the ramp, a minimum of two signal faces per ramp shall face entering traffic. For staggered operations, when the ramp control signals are operated such that green signal indications are not always displayed simultaneously to all of the lanes on the ramp, one signal face shall be proved over the appropriate center of each separately-controlled lane. It was realized by a nationwide survey that the two standards did not fully reflect the state-of-the-practice with respect to ramp metering operations. Due to the lack of significant conflicting movement at ramp meters, for any on-ramp lane, a minimum of one overhead mounted, or one upper and one lower roadside-mounted signal face is sufficient to control the ramp metering operations. The minimum necessary number of signal faces changes according to the total number of lanes, how the signal faces are mounted and how the meters are operated. The paper makes some suggestions on revising the two standards to better reflect the current nation-wide practices and better consider the specific operational needs for ramp meters.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/20460430
• Authors:
  • Wang, Zhongren
  • Dang, Vinh
• Publication Date: 2012

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Photos; References; Tables;
• Pagination: pp 73-82
• Serial:
  • International Journal of Transportation Science and Technology
  • Volume: 1
  • Issue Number: 1
  • Publisher: Elsevier
  • ISSN: 2046-0430
  • Serial URL: http://www.sciencedirect.com/science/journal/20460430

Subject/Index Terms

• TRT Terms: On ramps; Ramp metering; Signal head; Standardization; State of the practice; Traffic signals
• Identifier Terms: Manual on Uniform Traffic Control Devices
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 01447553
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 27 2012 4:42PM