A struck-by incident happens when a worker is hit by an object, vehicle, piece of equipment, or material, and the force of that impact causes the injury. That's what separates it from a caught-in or caught-between hazard, where a worker is pinned, crushed, or compressed between objects. With a struck-by, the object is moving, and the contact itself does the harm.

Struck-by hazards are one of construction's Fatal Four because the hazards are part of ordinary work tasks: a truck backing into a tight space, a load swinging overhead, a tool slipping off a scaffold, or exposure to traffic just feet from a crew. The impact can be serious, even when the task itself is routine.

The encouraging part is that struck-by incidents are predictable. They tend to happen where people on foot, moving equipment, materials, and vehicles share the same space without enough separation, visibility, or communication. That makes struck-by prevention a planning issue, and one contractors can manage with the right controls. This guide explains what struck-by hazards are, why they belong to the Fatal Four, the 3 jobsite conditions where struck-by risks commonly arise, how equipment blind spots put workers in danger, and the practical steps contractors can take to keep crews safe.

What Struck-By Hazards Are and Why They're One of Construction's Fatal Four

A struck-by incident happens when a worker is hit by an object, vehicle, piece of equipment, or material, and the force of that impact causes the injury. (1) That's what separates it from a caught-in or caught-between hazard, where a worker is pinned, crushed, or compressed between objects. With a struck-by, the object is moving, and the contact itself does the harm. (1)

The Occupational Safety and Health Administration (OSHA) sorts struck-by hazards into 4 types: (1)

Flying objects, like fragments from a grinder, a nail driven off-target, or material propelled by compressed air
Falling objects, like tools or materials dropping from a height, or a load released from rigging
Swinging objects, like a crane load or the rotating superstructure of an excavator or backhoe
Rolling objects, like a vehicle, a piece of equipment, or material moving at ground level

These hazards are part of OSHA's Construction Focus Four, often called the Fatal Four: falls, struck-by, electrocution, and caught-in/between. They earn that place because they're both common and deadly. Struck-by is the second leading cause of death among construction workers and the leading cause of nonfatal injuries in the industry. (2) In 2020 alone, struck-by incidents caused about 150 construction deaths and 14,000 nonfatal injuries, with roughly $1.4 billion in workers' compensation costs tied to the more serious nonfatal claims. (3)

One pattern stands out: about 75% of struck-by fatalities involve heavy equipment such as trucks, cranes, and other mobile machinery, usually in busy, changing work zones. (4) That's why so much of struck-by prevention comes down to managing where equipment and people move. It is also an OSHA-recognized construction hazard, so the same planning gaps that create exposure can also create compliance issues.

The 3 Most Common Struck-By Risks on the Jobsite

On many jobsites, struck-by risks commonly show up in 3 areas: mobile equipment, falling or swinging loads, and traffic. They share a root cause: workers on foot and moving hazards occupying the same space, but each calls for its own controls.

Mobile Equipment and Vehicle Struck-By Hazards

This is one of the most significant struck-by risk areas. Workers are struck when equipment backs up, turns, swings a load, or operates with limited visibility in a tight area. OSHA reports that about 1 in 4 struck-by-vehicle deaths involve construction workers. (4)

OSHA's motor vehicle standard sets clear ground rules. A vehicle with an obstructed rear view may not be used in reverse unless it has a reverse signal alarm audible above the surrounding noise, or unless it's backed only when a spotter signals that it's safe. (5) Vehicles must also be inspected at the start of each shift, covering brakes, tires, horn, steering, coupling devices, seat belts, and operating controls. (5) For material handling equipment such as high-lift rider trucks, OSHA requires overhead guards to protect operators from falling objects and roll-overs. (6)

The controls that matter most go beyond the equipment itself: separate travel routes for workers on foot and equipment, designated marked paths, pedestrian-free zones around active equipment, defined delivery and staging areas, swing-radius barricades around excavators and cranes, trained spotters when backing or working in tight spaces, and a firm rule that no one walks behind backing equipment.

Falling and Swinging Load Hazards

Workers are exposed to falling objects whenever they work or pass beneath cranes, scaffolds, or overhead activity, and to flying objects when tools or tasks send material airborne. (4)

The first goal is to keep objects from falling at all. OSHA requires hard hats wherever there's a danger of head injury from impact or from falling or flying objects, but a hard hat is the last layer, not the plan. (7) Source-level controls come first: using nets, barriers and toe-boards, securing tools with tethers and materials before overhead work begins, stacking and storing materials so they can't slide or collapse, keeping materials back from edges, and using toeboards, screens, guardrails, debris nets, canopies, or catch platforms to contain what could fall. (8) On scaffolds, this falling-object protection is required where work happens above other workers. (8)

Suspended loads deserve special care. Under OSHA's crane rules, workers must stay out of the fall zone, and loads must be planned, rigged, and moved in ways that limit exposure to workers below. (9) When a load does have to pass near workers, it must be rigged by a qualified rigger using hooks with self-closing latches or the equivalent, and a qualified signal person is required when the operator's view is obstructed, or the load isn't in full view. (9) The safest rule is simple: keep workers out from under suspended loads unless a specific task is unavoidable and even then ensure that layers of controls are in place.

Work Zone and Passing Traffic Hazards

Near roadways, the hazard runs both ways. OSHA notes a worker is about as likely to be struck by construction equipment inside the work zone as by a passing vehicle, so both need plans. (4) The trend is worth watching: the Bureau of Labor Statistics (BLS) recorded a rise in workers struck by vehicles in road work zones, from 48 in 2023 to 61 in 2024. (10)

OSHA requires construction areas to be posted with advanced warning and traffic control signs at the point of hazard, and the signs, signals, barricades, and devices used to protect workers must conform to Part 6 of the Manual on Uniform Traffic Control Devices (MUTCD). (11) The current MUTCD requires workers within the right-of-way and the temporary traffic control zone to wear high-visibility safety apparel meeting Performance Class 2 or 3 of ANSI/ISEA 107-2015 or an equivalent revision, and it sets qualification expectations for flaggers. (12) Even where a specific standard doesn't apply, OSHA uses the General Duty Clause to require high-visibility apparel and training for workers exposed to traffic in highway and road work zones. (13)

The controls here include temporary traffic control plans for the public, internal traffic control plans for on-site equipment, properly trained flaggers, channelizing devices and buffer space, positive protection or barriers where appropriate, and lighting suited to night work.

Heavy Equipment Blind Spots: The Hazard the Operator Can't See

Blind spots sit at the heart of mobile-equipment struck-by incidents, so they deserve their own attention. Every large machine, whether a backhoe, loader, dump truck, crane, telehandler, skid steer, or excavator, has areas the operator simply cannot see from the cab, especially to the rear and along the sides. Loads, attachments, and cab design make those zones larger. Noise, dust, night work, and crowded material staging make them more dangerous.

The mistake many crews make is treating blind spots as a worker-awareness problem ("watch where you're going") rather than a planning problem. The National Institute for Occupational Safety and Health (NIOSH) frames it the other way: the purpose of an internal traffic control plan (ITCP) is to separate vehicles and equipment from workers on foot as much as possible. (14) NIOSH also draws a useful line between the two kinds of traffic control: a temporary traffic control plan manages the public moving through a work zone, while an ITCP manages the construction vehicles and equipment operating inside it. (14) To help crews see what operators can't, NIOSH publishes blind-area diagrams for common construction vehicles. (14)

A backup alarm is a warning, not a traffic plan. Alarms can be drowned out by site noise or masked by a worker's hearing protection, and they do nothing about side and front blind spots. The stronger approach is to design the site so workers on foot and backing equipment don't need to share space in the first place: map blind spots during pre-task planning, set no-go zones, require agreed communication before anyone approaches a machine (without relying on eye contact alone), position trained spotters where conditions call for them, and give every worker stop-work authority when visibility is unclear. Cameras and proximity-detection systems can support the plan, but they don't replace separation, planning, and clear work zones.

Practical Steps to Prevent Struck-By Incidents on the Jobsite

Struck-by prevention works best as a system built before the shift starts, not a set of reminders shouted during it. A practical sequence looks like this:

Start with a hazard assessment. Before each task or shift, identify what equipment will move, where workers on foot will be, what loads will be lifted, where materials could fall, where backing or swinging or dumping will happen, where public traffic is present, and what has changed since yesterday.
Build an internal traffic control plan. Map equipment routes, worker walkways, no-go zones, backing restrictions, delivery routes, staging areas, entry and exit points, and how crews will communicate. On multi-employer jobsites, the plan should also spell out how routes, delivery areas, exclusion zones, and changing conditions are communicated across subcontractors.
Separate people from equipment and loads. Use barricades, cones, worker-free zones, equipment-only routes, swing-radius barriers, and exclusion zones beneath overhead work.
Control backing. Design the site to minimize backing, use pull-through staging where possible, verify backup alarms, use spotters when needed, and enforce the no-walk-behind rule.
Secure falling-object hazards. Tether tools where appropriate, stack and store materials safely, barricade areas below overhead work, inspect rigging and lifting hardware, and keep housekeeping under control.
Plan lifts. Confirm load weight and capacity, use qualified riggers and tag lines where appropriate, keep nonessential workers out of the fall zone, and stop work if communication is lost.
Manage traffic exposure. Use MUTCD-aligned traffic control, trained flaggers, the right class of high-visibility apparel, buffer space, and a daily check of the traffic control setup.
Train operators and workers together. Cover blind spots, approach and backing rules, swing-radius and fall-zone hazards, falling-object prevention, high-visibility requirements, and stop-work authority.
Make supervisors accountable. Verify controls are in place before work begins, equipment and alarms are working, materials are secured, overhead areas are barricaded, and near misses are reviewed and used to update the plan.

A few patterns show up again and again on jobsites where struck-by exposure is high: no internal traffic plan, workers crossing equipment paths to reach materials or break areas, spotters used without clear signals or safe positioning, unbarricaded swing radii, deliveries arriving without direction, and multi-employer sites with no shared communication plan. Each one can be addressed with better planning, communication, and follow-through.

How GMG EnviroSafe Helps Contractors Reduce Struck-By Hazards

Struck-by incidents don't happen in isolation. They happen where equipment, materials, and people cross paths, which means the most reliable fixes are built into how a site is planned and supervised, not bolted on after an incident.

GMG EnviroSafe works alongside construction clients to identify those crossing points and reduce struck-by exposure through practical, site-specific controls. Our hands-on support commonly includes:

Jobsite struck-by hazard assessments and job hazard analysis
Internal traffic control and blind-spot safety reviews
Falling-object and overhead-work control reviews
Traffic control and high-visibility personal protective equipment (PPE) program guidance
Mobile equipment and vehicle safety procedures
Supervisor and crew training, including toolbox talks
Documentation, corrective-action tracking, and OSHA construction readiness support

Struck-by prevention doesn't need to be complicated, but it does require planning. We help manage the details so your crews stay focused, visible, and protected on the jobsite.

Want to know where your struck-by prevention program stands? GMG EnviroSafe can help review your jobsite, identify practical improvements, and strengthen your safety program before crews get to work.

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Sources

OSHA. Construction Focus Four: Struck-By Hazards. osha.gov
CPWR (The Center for Construction Research and Training). Struck-By Hazards. cpwr.com
NIOSH. Struck-By Injuries in the Construction Sector (2020 data). cdc.gov/niosh
OSHA. Construction eTool: Struck-By. osha.gov/etools/construction/struck-by
OSHA. 29 CFR 1926.601, Motor Vehicles. osha.gov
OSHA. 29 CFR 1926.602, Material Handling Equipment. osha.gov
OSHA. 29 CFR 1926.100, Head Protection. osha.gov
OSHA. 29 CFR 1926.451(h), Falling Object Protection. osha.gov
OSHA. 29 CFR 1926.1425, Keeping Clear of the Load. osha.gov
BLS. National Census of Fatal Occupational Injuries in 2024. bls.gov
OSHA. 29 CFR 1926 Subpart G, Signs, Signals, and Barricades. osha.gov
FHWA. Manual on Uniform Traffic Control Devices (MUTCD), 11th Edition, Part 6. mutcd.fhwa.dot.gov
OSHA. Standard Interpretation: High-Visibility Warning Garments. osha.gov
NIOSH. Using Internal Traffic Control Plans to Prevent Construction Worker Injuries and Fatalities in Work Zones. cdc.gov/niosh