Dickinson District trainer reviews guardrail inspection basics, timelines and common defects

Dennis, a Dickinson District staff member, delivered a virtual training on guardrail inspection basics for Department of Transportation projects, focusing on plan review, specification requirements and common field defects. "I chose to focus on the basics of guardrail inspection," he said, noting the session was intended as a refresher for district inspectors.

The training matters because guardrail protects motorists from steep slopes, bridge piers and other roadside hazards; inspectors must confirm installations meet contract plans, standard drawings and specification limits before acceptance. Dennis repeatedly cited Section 7 64 of the specification book and the Highway Barrier Pocketbook as guidance for scheduling, installation tolerances and acceptable hardware.

Dennis told attendees to start inspections with the project plans (often the Section 130 sheets) to confirm whether guardrail is new or a remove-and-reset, to check material and quantity tables, and to verify whether traffic control is required while guardrail is removed. He said contractors must provide a written schedule for guardrail work (Section 7 64) and that “controlling items” such as asphalt removal and base work should have short lapses between activities; he noted the specification’s requirement that each individual run be installed within 10 working days from the date all controlling items allow installation to begin. He also said plan notes typically state whether some guardrail components must be delivered to a DOT facility or become contractor property.

On installation tolerances and hardware, Dennis summarized standard-drawing and specification requirements: posts are typically wood except the last two posts at the terminal, posts for MGS systems are driven to 32 inches above ground and the rail height is shown as 31 inches with a 1-inch tolerance on height. He noted rail panels are commonly 12.5 or 25 feet and cautioned inspectors to check splice details (for example, avoid a center bolt in the midspan slot) and lap direction (lap toward direction of travel to reduce snagging). Reflectors should be mounted on offset blocks and spaced at 25-foot centers for runs under 250 feet and 50-foot centers for runs over 250 feet.

Dennis reviewed removal and reset practices: check the condition of existing guardrail before authorizing a reset; pieces showing rail deflection, flattening, non-manufactured holes, splice tears or other defects should not be reused. He recommended using the Highway Barrier Pocketbook to identify unacceptable pieces and advised districts to confirm barrier-modification plate dimensions (he highlighted a 1 foot 6 inch plate dimension from his plans) to avoid incorrect post spacing that later requires rework.

Common field deficiencies Dennis showed from past inspections included loose or missing bolts and nuts, loose retainer or bearing plates, leaning or rotated posts, block rotation, partially filled cold mix around posts, extra non-manufactured holes, detached terminals and loose cable anchors. He emphasized working with contractors to correct deficiencies during installation and encouraged final, documented inspections using available checklists on the DOT training site. He also suggested inviting maintenance/guardrail installers to review completed systems before final acceptance because those crews take over long-term upkeep.

Dennis closed with takeaways: check condition early if guardrail will be reset; require and enforce a schedule on roads open to public traffic; confirm barrier-modification dimensions match plans and standard drawings; use an inspection checklist and resolve installation deficiencies before accepting the work. "Get a checklist to inspect the guardrail system," he said, and provided contact information for follow-up questions.

The presentation included numerous photo examples and references to DOT plan sections and standard drawings; there were no formal votes or actions recorded during the session.