When are Positive Protection Barriers Appropriate?
Federal Law & Standards
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2005 - Congress calls for Positive Protection
Under section 1110 of SAFETEA-LU, Congress enacted 23 USC 109(e)(2) and 112(g) which call for positive protection “between workers and motorized traffic".
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2007 - FHWA adopts Temporary Traffic Control Devices Rule ("Subpart K")
FHWA adopted Subpart K (23 CFR 630.1102 et seq.) pursuant to the mandate in SAFETEA-LU. 23 CFR 630.1108(a) of Subpart K lists 5 circumstances under which practitioners need to (“shall”) consider use of positive protection.
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2010 - ANSI establishes National Standard for Work Zone Safety
ANSI Standard A10.47 (§4.4) provides that positive protection “shall be considered” in, at minimum, the 5 circumstances .
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2021 - ANSI updates National Standard for Work Zone Safety
ANSI Standard A10.47-2021 (§4.4) provides that positive protection “shall be used” in, at minimum, the 5 circumstances .
Positive Protection are measures “between workers and motorized traffic” which “contain and/or redirect vehicles" and meet applicable crashworthiness criteria . 1, 2
Positive Protection may include highly mobile barrier, movable and temporary steel barrier, movable concrete barrier, traditional concrete barrier, associated cushions, and other strategies to avoid traffic accidents in work zones including full road closure. 3
Mobile and other movable barriers enable field crews to quickly create work spaces that are physically separated from moving traffic and quickly removed from the roadway once the work is completed.
Federal Law
The statutes and underlying regulations, read together, call for positive protection (barrier) “between workers and motorized traffic” which “contain and/or redirect” errant vehicles and meet applicable
crashworthiness criteria
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1
,
2
Circumstances under which positive protection needs to ("shall") be considered:
“At a minimum, positive protection devices shall be considered in work zone situations that place workers at increased risk from motorized traffic, and where positive protection devices offer the highest potential for increased safety for workers and road users, such as:
- Work zones that provide workers no means of escape from motorized traffic (e.g., tunnels, bridges, etc.);
- Long duration work zones (e.g., two weeks or more) resulting in substantial worker exposure to motorized traffic;
- Projects with high anticipated operating speeds (e.g., 45 mph or greater), especially when combined with high traffic volumes;
- Work operations that place workers close to travel lanes open to traffic; and
- Roadside hazards, such as drop-offs or unfinished bridge decks, that will remain in place overnight or longer." 10
Separate Pay Items:
Federal statutes require a “separate pay item” for positive protection. 1 , 11
ANSI Standards
ANSI Standard A10.47-2021 (§4.4) likewise provides that positive protection measures “shall be used (unless determined unnecessary)” when any of the following exist:
- Work zones that provide employees no means of escape (e.g. tunnels, bridges, etc.) from external motorized traffic intruding into the work space.
- Long duration work zones (e.g. two weeks or more) resulting in substantial employee exposure to motorized traffic.
- Projects with high anticipated operating speeds (e.g. ≥ 45 mph, 72 km/h) especially when combined with high traffic volumes (> 20,000 vehicles per day).
- Work operations that place workers within one lane width to travel lanes open to traffic.
- Roadside hazards, such as drop-offs or unfinished bridge decks, that will remain in place overnight or longer.
ANSI Standard A10.47-2021 further notes that there might be other circumstances not listed that merit the use of positive protection.
ANSI Standard A10.47-2021 (§4.4.1) also notes that "positive protection may only be determined unnecessary if":
- There is a written analysis by the project sponsor supporting such a conclusion,
- And the project is outside an urban area,
- And the average daily traffic load of applicable road is less than 100 vehicles per hour.