Signs, Barricades, and Temporary Traffic Control

A missing warning sign or a displaced traffic drum can create confusion at exactly the wrong moment. Drivers may brake suddenly, enter a closed lane, or travel too close to workers and equipment.

For highway construction, quarry access areas, and maintenance operations, temporary traffic control needs attention throughout the job. Proper placement gives drivers clear directions before they reach a hazard. Regular inspections help keep those directions visible and accurate as work progresses.

Start With a Plan That Fits the Work

Before installing signs, cones, drums, or barricades, review the approved traffic control plan and applicable agency or project requirements. A trained, designated person should oversee placement, inspections, and necessary changes.

The arrangement must account for conditions at the site, including traffic speeds, curves, hills, intersections, truck entrances, pedestrians, and nighttime visibility. Sign spacing, device spacing, and transition lengths should follow the plan and suit the operation.

Protect the workers installing and removing devices, too. Establish safe procedures that address high-visibility PPE, communications, and protective vehicles where required. Moving a fallen cone should never mean stepping into traffic without appropriate protection.

Give Drivers Clear, Consistent Guidance

Advance warning signs need to be visible early enough for drivers to read the message and respond before reaching a lane shift, closure, or flagger. Vegetation, parked trucks, curves, and other signs can obstruct the view.

Cones, drums, and barricades should define a continuous, recognizable route. Follow the planned layout, keep devices out of the usable travel lane, and maintain required buffer spaces. Preserve safe truck entrances, emergency access, and designated pedestrian routes.

Use approved supports and ballast according to manufacturer and agency instructions. Improvised weights, such as rocks or concrete blocks, can introduce additional hazards if struck.

Crews also need to understand what each device can do. Cones, drums, and ordinary barricades guide or restrict movement; they do not provide vehicle-impact protection. Use properly designed barriers or other protective systems when required.

Inspect Throughout the Shift

A correct setup can become unsafe after wind, vehicle contact, equipment movement, or changing work conditions. Inspect the full approach and travel path before opening the arrangement to traffic, then recheck as conditions change.

Routine inspections should address:

• Visibility: Clean dirt, dust, and mud from signs and reflective surfaces. Check nighttime visibility after dark.
• Condition: Replace devices that are faded, damaged, unstable, or inadequately reflective.
• Position: Look for fallen cones, shifted drums, leaning signs, and damaged barricades. Restore them using the established safe procedure.
• Operation: Check warning lights, arrow boards, and electronic message signs for correct displays, reliable power, and proper operation.

Review the arrangement from the driver’s viewpoint. A sign that is easy to see while standing beside it may be difficult to recognize from an approaching vehicle.

Respond When Conditions Change

Long queues, sudden driver maneuvers, repeated device displacement, or an unprotected work area are reasons to stop and reassess. Notify the designated traffic control lead so the arrangement can be reviewed and corrected.

Keep messages current as the job changes. Remove or cover signs when their messages no longer apply, and remove unnecessary devices when authorized. Clear, accurate guidance helps drivers understand what to expect and where to go.

Download the one-page handouts below for your next toolbox talk, pre-shift briefing, or traffic control inspection review.