The National Academies

NCHRP 17-06A [Completed]

Service Vehicle Lighting and Traffic Control Systems for Short-Term and Moving Work Zones (Phase II)

  Project Data
Funds: $252,277
Research Agency: Transportation Research Corp.
Principal Investigator: Fred R. Hanscom
Effective Date: 10/15/1984
Completion Date: 5/16/1990

Construction and maintenance work on or adjacent to the highway has been recognized as presenting special hazards both to the motorist and to workers. Most of the research to date has been directed at traffic control measures for use in relatively long-term work zones that generally involve extensive control treatments. Service vehicles moving slowing or stopped temporarily on or adjacent to the travel lanes also present a serious driving hazard, as evidenced by the substantial number of accidents involving such equipment. However, installing and removing an elaborate traffic control layout for these situations may be more hazardous than performing the service operation with a simpler system.

Uniform and comprehensive guidelines are not available for signal lighting systems on service vehicles or for traffic control measures in short-term and moving operations. Research is needed to develop and evaluate such systems and measures that will be effective and efficient. The number of possible situations is too great to define a specific treatment for each; nonetheless, there is a need to provide information regarding the types of treatment that have been or promise to be successful for typical situations. These guidelines would be used by state and local agencies, as well as utility companies, to determine the best treatments for their specific activities.

The objective of this project was to develop guidelines for warning systems on service vehicles and for traffic control in short-term, intermittent moving, and continuously moving work zones. In addition to considering the basic traffic and safety requirements, the guidelines were to also place emphasis on the operational efficiency and cost-effectiveness of each treatment

. This research consisted of two phases. Phase I determined the state of the art through a literature review and contacts. Promising techniques, problems with current practice, and the feasibility and desirability of developing standards were identified. The factors affecting short-term, intermittent moving, and continuous moving activities were identified including type of facility; roadway width, number of lanes, shoulder characteristics, area type, traffic volume and speed, physical sight restriction, adverse visibility, activity period (e.g., day or night, peak or off-peak), duration of activity, length of work zones, extent of lane encroachment, lane blockage, and speed of operation. Service vehicle warning and traffic control systems were developed for each work-type situation. For signal lighting, consideration was given to the effects of color, flash characteristics, number, size, and intensity, as well as the environment in which the vehicle is operating. Other vehicle warning devices such as arrow boards, flags, and vehicle paint schemes were also considered. The traffic control systems include the use, as appropriate, of flagmen, vehicles (e.g., barrier, shadow), and traffic control devices (e.g., signs, channelizing devices, arrow panels). Spacing and size of devices, as well as the placement and number of all elements, are included. In development of the alternatives, consideration was given to the information needs of the motorist, equipment availability, characteristics of service vehicles, cost-effectiveness, portability, traffic operations, and motorist and worker safety (including the added hazard due to the placement and removal of devices).

In Phase II, indoor laboratory studies were conducted to evaluate and optimize the vehicle warning and traffic control systems. Closed field studies were conducted to further test the most promising systems. Field tests under actual highway conditions using real or simulated work activities were conducted as a final validation of each system. An operations guide was prepared to facilitate direct incorporation into state and local manuals used by service personnel in short-term and moving work zones.

Status: Research has been completed and the final report has been published as NCHRP Report 337.

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