Work Zone Intrusions: Cones Communicate, They Do Not Protect

Chris Fredette
11 hours ago
6 min read

Between 2015 and 2024, fatal worker injuries at road construction sites ranged from 82 to 143 per year, according to the National Work Zone Safety Information Clearinghouse using Bureau of Labor Statistics Census of Fatal Occupational Injuries data. Across 2022 to 2024, about 52.7 percent of those deaths were workers on foot struck by a motor vehicle and another 24.8 percent were workers killed as a driver or passenger in a motor vehicle crash. Roughly three quarters die because a vehicle hit them or the machine they were in.

On the night of August 17, 2026, a 26-year-old forklift operator was killed when a semi struck the forklift he was operating inside an active work zone on Interstate 41 near Scheuring Road in De Pere, Wisconsin. The semi driver was not injured. The Wisconsin State Patrol, including its Technical Reconstruction Unit, is investigating and no charges or citations had been announced as of publication. Nothing here speculates about cause or fault.

Independent of any single incident, the dominant fatal mechanism in road work is an outside vehicle entering the space where people are working. Most work zone programs are built around preventing that. Very few are built around surviving it.

The Standards That Apply, and the One That Does Not

Temporary traffic control in construction lives in 29 CFR 1926 Subpart G, which now consists of two sections. The load-bearing one is 1926.200. Its paragraph (g) requires construction areas to be posted with legible traffic control signs at points of hazard, and ties the design and use of all traffic control devices, including signs, signals, markings and barricades, to Part 6 of the Manual on Uniform Traffic Control Devices. 1926.201(a) adds the flagger rule: signaling by flaggers and the use of flaggers, including warning garments worn by flaggers, must conform to Part 6.

Two details matter if you are checking a citation. The version OSHA enforces is the MUTCD 2009 Edition with Revisions 1 and 2, incorporated by reference at 29 CFR 1926.6, not the current FHWA edition. And Subpart G no longer has a separate section for barricades. They ride inside 1926.200(g).

High-visibility apparel is the requirement most often stated too broadly. The MUTCD reference in 1926.201(a) reaches flaggers. Federal OSHA has no construction standard of general application requiring high-visibility apparel for non-flagger workers exposed to vehicle traffic, and addresses those exposures under Section 5(a)(1) of the OSH Act. Excavation work is the exception: 1926.651(d) requires employees exposed to vehicular traffic to wear warning vests or other suitable reflectorized or high-visibility garments.

Equipment inside the zone brings its own standards. 1926.601 covers motor vehicles operating within an off-highway jobsite not open to public traffic: brakes at (b)(1), an audible warning device at the operator station at (b)(3), a reverse signal alarm where the rear view is obstructed at (b)(4). That coverage clause matters on road work, because a jobsite open to public traffic may fall outside it. 1926.602(d) adopts the powered industrial truck operator training requirements of 29 CFR 1910.178(l) for construction.

Here is the part worth being precise about. None of these standards regulate a driver who intrudes into a work zone from the traveling public. OSHA's authority runs to employers, and on a multi-employer worksite an employer can be cited for conditions exposing another employer's employees under the controlling, creating, correcting and exposing categories. It does not extend to members of the public. A motorist who leaves a travel lane is a matter for state law enforcement and the state DOT. That is why so many work zone intrusion fatalities produce a state patrol reconstruction and no OSHA citation, and exactly why a contractor cannot treat compliance as the whole of the protection plan.

Exposure Control, Not Just Visibility

Most temporary traffic control plans are visibility plans. Cones, drums, signs, arrow boards and vests work by making the zone legible to a driver who is paying attention. That is a reasonable first line, and it fails in exactly the circumstances most common in road work: night operations, fatigued or impaired drivers, and heavy vehicles whose stopping distance exceeds the taper a plan provides.

The design question is different from the visibility question. It is: if a vehicle leaves the travel lane at this location, where does it end up, and what is between it and our people?

That question produces different answers than a standard plan does. It produces positive protection, meaning barrier with mass rather than channelizing devices: portable concrete barrier, truck or trailer-mounted attenuators, and shadow vehicles upstream of the crew. It produces buffer space, longitudinal and lateral, treated as a design element rather than leftover room. It produces internal traffic control plans separating workers on foot from equipment moving inside the zone, a hazard the public never touches. And it produces a spotter whose only assignment is watching approaching traffic.

Night work compounds it. Depth perception, closing speed judgment and reaction time degrade, for the driver and for the worker on foot. A plan adequate at 2 p.m. can be inadequate at 2 a.m. with the same signage.

A Work Zone Walk You Can Run Before the Shift

This takes about ten minutes and is worth running at the start of every shift, not once at mobilization.

Stand at each work location and identify the intrusion path: if a vehicle leaves the lane here, what is its trajectory and what stops it.
Distinguish channelizing devices from positive protection out loud, so nobody confuses a line of drums with a barrier.
Confirm the buffer space in the plan still exists on the ground, because it is the first thing that gets consumed as materials and equipment stage.
Assign a traffic spotter with no other duties, confirm how they will signal, and confirm every worker on foot knows the signal and the escape route.
Separate workers on foot from equipment operating inside the zone, and make sure backing operations have a spotter and a defined path.
Check that flagger stations, signs, taper lengths and device spacing match the MUTCD-based plan and were not shortened for convenience, and that high-visibility apparel suits the light conditions of this shift.
Reassess after any change to lane closures, shift timing, weather or equipment position, and treat that reassessment as a required step rather than a courtesy.

Questions Crews Ask About Work Zone Protection

Do cones and drums count as protection?

No. Channelizing devices delineate a work zone and communicate its geometry. They are not designed to redirect or stop a vehicle and they do not reduce the severity of an intrusion. Positive protection means a device with the mass and structural design to redirect an errant vehicle, such as portable concrete barrier or a crash attenuator.

Will OSHA cite the contractor when a member of the public drives into a work zone?

Not necessarily, and often not. If the intruding driver is not an employee of any employer on the site and the traffic control conformed to the MUTCD-based plan, there may be no citable violation even where a worker died. That is a legal outcome, not a safety outcome, and it should not be read as a finding that the protection was adequate.

What is an internal traffic control plan?

It governs movement of construction vehicles and equipment inside the closed work area, as distinct from public traffic outside it. It addresses backing, blind spots, pedestrian routes and equipment paths. Workers struck by their own project's equipment are a meaningful share of road work fatalities, and the public traffic control plan does nothing about them.

Key Takeaways

About three quarters of worker fatalities at road construction sites between 2022 and 2024 involved a motor vehicle striking a worker on foot or the vehicle the worker occupied, per the National Work Zone Safety Information Clearinghouse using BLS CFOI data.
29 CFR 1926.200(g) ties the design and use of all traffic control devices to Part 6 of the MUTCD, while 1926.201(a) covers flagger signaling and flagger warning garments. Federal OSHA has no general high-visibility apparel standard for non-flagger construction workers.
OSHA has no authority over an intruding driver from the traveling public, so a clean compliance record is not evidence that the protection plan was adequate.
Channelizing devices communicate. Only positive protection with mass changes the outcome of an intrusion.
Night work degrades the assumptions a daytime plan is built on, and internal traffic control deserves the same attention as public traffic control.

Have Your Traffic Control Plan Reviewed Against the Work You Are Actually Doing

TriCore Safety reviews and writes site-specific safety plans and written programs for construction work, including temporary and internal traffic control procedures, spotter and flagger roles, and the shift-level reassessment that keeps a plan current as a job changes. If your plan was written at mobilization and the work has moved since, that gap is worth closing before the next night shift.

Request a consultation at tricoresafety.com. Related reading: The Fatal Four: Why the Same Four Hazards Keep Killing Construction Workers.