Barriers and Positive Protection
When channelizing devices are not enough, positive protection physically separates traffic from workers or hazards. Portable barriers, K-rail, crash cushions, attenuators, and steel plates each play a defined role.
Last reviewed: June 24, 2026
Why It Matters
- Cones and drums warn and channelize but do not stop a vehicle; positive protection is what physically shields workers and road users when the risk warrants it.
- Exposed barrier ends and improperly placed protection are serious, high-consequence findings.
When It Applies
- Where the speed, exposure, or hazard calls for a physical barrier rather than channelizing alone — the need is determined by the plan and agency requirements.
Planning Considerations
- Identify where positive protection is required and specify the system — portable concrete barrier / K-rail, crash cushions or attenuators at exposed ends, and steel plates over open excavations.
- Barrier placement, end treatments, and deflection distances come from agency standard plans and the approved plan; verify these rather than assuming.
Field Considerations
- Install barriers to the planned alignment, protect exposed ends with the specified crash cushion or attenuator, and secure steel plates against shifting.
- Keep the area behind the barrier clear as intended and maintain the system through the work.
Inspection Considerations
- Inspectors check for protected barrier ends, correct placement, and secured steel plates.
- Exposed or blunt barrier ends and unsecured plates are common, serious findings.
Common Compliance Failures
- Exposed barrier ends without a crash cushion or attenuator.
- Steel plates that are unsecured, unramped, or slippery when wet.
Upstream Prevention
- Determine where positive protection is required during planning and show end treatments on the plan.
- Verify placement, end-treatment, and plating requirements against agency standard plans.
Related Pages
Official Sources
Frequently Asked Questions
What is positive protection in a work zone?
Positive protection uses physical barriers — like concrete barrier or crash cushions — to separate traffic from workers, instead of relying on cones or signs. Whether it's required depends on the risk, the standard, and the approved plan.
When is a barrier required instead of cones?
A barrier is generally used where the exposure and risk are high enough that physical separation is warranted. The specific requirement comes from the agency, the standard, and the approved plan, and should be verified for the project.