Toolbox for Work Zone Barriers

 

Excerpts from Transportation Planner's Safety Desk Reference

These excerpts from Transportation Planner's Safety Desk Reference focus on Work Zone Planning.

For the complete document, go to http://tsp.trb.org/assets/FR_Safety%20Planner_1_17_07FINAL.pdf.

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All material preceding the Work Zone Collision section has been deleted.

Work Zone Collisions

Problem Description

The safe and efficient flow of traffic through work zones is a high priority for transportation officials and the motoring public. Work zones are estimated to contribute 10 percent of all congestion in the United States. According to the FHWA, as congestion builds within and approaching work zones, crash rates increase. Additionally, the safety of workers in work zones is of primary importance. Roadway workers are killed at a rate nearly three times as high as other construction workers and eight times higher than general industry workers.

The need for continued focus on work zone safety becomes more apparent because of the current emphasis on system preservation rather than construction of new facilities. In 2000, the share of capital funds used for system preservation was 52 percent and this percentage is expected to continue to rise. Thirteen percent of the National Highway system is under construction each year, during the peak summer work season (Wunderlich and Hardesty, 2003). This section provides information on the various countermeasures that have been effective in addressing work zone collisions. Working with safety practitioners will be important in choosing the most effective approach.

Data

According to 2005 FARS data:

More than one-half of all fatal work zone crashes occurred during the day;

Twenty-eight percent of work zone fatal crashes occurred on either urban or rural Interstates;

  • Overall, slightly more fatal crashes occurred in urban work zones than in rural work zones;
  • Fifty-seven percent of work zone fatal crashes occurred on roads with a posted speed limit of 55 mph or greater; and
  • Single-vehicle crashes accounted for one-half of all work zone fatal crashes.

Other facts regarding work zone safety include:

  • Heavy trucks were involved in more than 20 percent of fatal work zone crashes (FMCSA, 2004); and
  • Alcohol was involved in 39 percent of fatal work zone crashes in 2003 (National Work Zone Safety Information Clearinghouse).

Objective 1. Reduce the Number, Duration, and Impact of Work Zones

Strategies

Reducing the number of work zones and the length of time work zones are set up will reduce the exposure of drivers and workers to crashes. Strategies include:

  • Improve maintenance and construction practices to accelerate construction and manage assets better (P, $$$);
  • Utilize full-time roadway closure for construction operations to complete work faster, more cost-effectively, and more safely (T, $);
  • Utilize time-related contract provisions to ensure that construction schedules are as efficient as possible (P, $$);
  • Use nighttime road work so that work is conducted during less heavily trafficked periods and exposure is reduced (P, $);
  • Use demand management programs, such as carpooling, vanpooling, and transit, to reduce volume through work zones (P, $$$); and
  • Design future work zone capacity into new or reconstructed highways and make work zone considerations an explicit tradeoff on decision-making for new construction and reconstruction (T, $$$$).

Objective 2. Improve Work Zone Traffic Control Devices

Strategies

Traffic control devices are used to communicate with drivers in advance of and within work zones. It is important to inform the driver of the desired actions and the correct path through the work zone. ITS also can be used to inform drivers of delays and alternative routes. Strategies include:

  • Implement ITS strategies to improve safety (E, $$);
  • Improve visibility of work zone traffic control devices (T, $$); and
  • Improve visibility of work zone personnel and vehicles (varies, $$).

Objective 3. Improve Work Zone Design Practices

Strategies

Changes in the basic approach to designing work zones may offer opportunities for improved safety:

  • Establish work zone design guidance on topics, such as lane transitions, lane widths, and edge drop-offs (T,$);
  • Implement measures to reduce work space intrusions and limit consequences of intrusions (T, $$$); and
  • Improve work zone safety for pedestrians, bicyclists, motorcyclists, and heavy-truck drivers (T, $$$).

Objective 4. Improve Driver Compliance with Work Zone Traffic Controls

Strategies

Frequent and visible enforcement is generally accepted as highly effective in gaining compliance with traffic laws and regulations in work zones. The physical presence of a law enforcement officer in the work zone is the most effective way to maximize compliance.

Strategies include:

  • Enhance enforcement of traffic laws in work zones (T, $$), including automated enforcement;
  • Improve credibility of signs (E, $) by ensuring that they are updated to reflect actual conditions and are informative; and
  • Improve application of increased driver penalties in work zones (T, $).

Objective 5. Increase Knowledge and Awareness of Work Zones

Strategies

Public information and education campaigns can be used to educate drivers on work zone safety issues at both a high level and a project level. Training programs for staff who design work zones also are important. Strategies include:

  • Disseminate work zone safety information to road users, such as work zone information on DOT web sites (T, $$); and
  • Provide work zone training programs and manuals for designers and field staff (T, $).

Objective 6. Develop Procedures to Effectively Manage Work Zones

Strategies

  • Develop or enhance agency-level work zone crash data systems that include data beyond that in a crash database on a range of aspects of each work zone (T, $$);
  • Improve coordination, planning, and scheduling of work activities, such as coordinating a series of work zones along a corridor (T, $$);
  • Use incentives to create and operate safer work zones, such as award programs to recognize the best outreach and training programs on work zone safety (T, $$); and
  • Implement work zone quality assurance procedures, such as safety inspections or audits (T, $$).

Best Practices

Virginia DOT's Work Area Protection Manual:

http://www.virginiadot.org/business/resources/1-%20WEBwapmCOVER.pdf.

Work Area Protection Guide, Illinois DOT, Bureau of Operations, 1997 order form:

http://www.dot.state.il.us/blr/publication.html.

Illinois Bureau of Design and Environment Manual, 2002 Edition:

http://www.dot.state.il.us/desenv/bdemanual.html.

Washington State DOT's Design Manual:

http://www.wsdot.wa.gov/fasc/engineeringpublications/manuals/designmanual.pdf.

Resources

NCHRP Report 500 Volume 17: A Guide for Reducing Work Zone Collisions:

http://safety.transportation.org/guides.aspx.

National Work Zone Safety Information Clearinghouse:

http://wzsafety.tamu.edu/.

NCHRP Synthesis 215: Determination of Contract Time for Highway Construction Projects:

http://www.trb.org/news/blurb_detail.asp?id=3342.

FHWA Make Work Zones Better Workshop:

http://www.fhwa.dot.gov/construction/washto02/zones.htm.

FHWA Work Zone Mobility and Safety Program Best Practices Guide:

http://ops.fhwa.dot.gov/wz/practices/practices.htm.

National Work Zone Safety Awareness Week cosponsored by the FHWA and AASHTO:

http://safety.fhwa.dot.gov/wz/wz_awareness.htm.

 

 

 

 

 

 

The purpose of this site is to help plan Work Zones.

The basic idea is to present basic information about barriers and attentuators in a format that will allow quick comparisons in support of Work Zone planning. The primary sources of the information presented here are NCHRP 350 approval letters. The next steps in developing these pages are to improve the information presented and to review the presentation format. This will require practitioner input.

This site is hosted by AHMCT at UC Davis. The content of these pages reflects work in progress. Please send comments to ahmctWeb (at) ucdavis.edu.