Traffic Control and Work Zone Safety JHA (Job Hazard Analysis / Activity Hazard Analysis)

Updated 2026-06-23

A Traffic Control and Work Zone Safety JHA (Job Hazard Analysis / Activity Hazard Analysis) is the plan that keeps workers in a roadway work zone from being struck by passing traffic or by the construction equipment operating around them. Work zones place crews on foot within feet of live traffic moving at speed, and the struck-by-vehicle hazard is one of the leading causes of construction worker deaths. This guide walks through building a Traffic Control and Work Zone Safety JHA that names the struck-by-traffic, equipment, and flagger hazards and assigns the temporary-traffic-control, visibility, and separation controls that hold up in the field.

Why traffic control and work zone safety need their own JHA

A roadway work zone is a uniquely dangerous environment because the primary hazard — vehicles driven by the public at speed — is outside the contractor's control. Drivers are distracted, speeding, impaired, or simply fail to see the work zone, and a worker on foot struck by a vehicle is often killed. On top of the public traffic, construction equipment and trucks operate within the work zone, creating an internal struck-by hazard, and flaggers stand directly in harm's way to control traffic. Managing a work zone requires a temporary traffic control plan that conforms to the MUTCD, deliberate separation of workers from traffic, and disciplined internal traffic control. The hazard profile justifies a dedicated JHA.

Breaking work zone safety into steps

The steps for a Traffic Control and Work Zone Safety JHA follow the zone from setup to removal:

  • Develop the temporary traffic control plan per the MUTCD
  • Set up advance warning signs, tapers, and channelizing devices
  • Establish the buffer space and the work area
  • Position flaggers and the internal traffic control plan
  • Separate workers and equipment from live traffic
  • Perform the work within the protected zone
  • Maintain the work zone and adjust for conditions
  • Remove the work zone safely in reverse

Each step carries a hazard, and the temporary traffic control setup and the worker-traffic separation are where struck-by deaths are prevented.

The hazards step by step

Struck-by public traffic

This is the defining and deadliest hazard. Workers on foot in or beside a live roadway are struck by passing vehicles. The controls are a temporary traffic control plan conforming to the MUTCD — advance warning signs, proper tapers, channelizing devices, and speed reduction — to guide and slow traffic; a buffer space between traffic and workers; positive protection (barriers or barricades) for higher-speed or longer-duration work; high-visibility apparel meeting the required class; and, where feasible, closing lanes or roads to create physical separation rather than relying on cones alone. The greater the speed and exposure, the more substantial the protection must be.

Struck-by construction equipment

Inside the work zone, construction equipment and trucks operate around workers on foot, creating an internal struck-by hazard separate from public traffic. The controls are an internal traffic control plan that separates equipment from workers, spotters and backing plans for equipment, minimizing backing, high-visibility apparel, and workers maintaining awareness and positive communication with operators. The internal hazard kills workers too, and it is often overlooked in favor of the public traffic.

Flagger exposure

Flaggers stand in or beside live traffic to control it, putting them directly in the struck-by zone. The controls are trained flaggers using proper signaling devices and procedures, high-visibility apparel, an escape route planned in case a vehicle does not stop, positioning the flagger where they are visible and have protection where possible, and not positioning flaggers where they have no way to get clear.

Visibility and night work

Reduced visibility at night and in poor weather increases the struck-by risk. The controls are work-zone lighting, retroreflective high-visibility apparel and devices, and enhanced traffic control for low-visibility conditions.

A simple Traffic Control and Work Zone Safety JHA structure

StepHazardControlStandard
Plan the zoneInadequate controlMUTCD-conforming temporary traffic control planMUTCD / OSHA 1926.200(g)
Set up devicesStruck-by trafficAdvance warning, tapers, channelizing devices, bufferMUTCD
Protect workersStruck-by trafficPositive barriers, lane closure, high-visibility apparelOSHA 1926.201 / 1926.95
Internal trafficStruck-by equipmentInternal traffic control plan, spotters, backing planOSHA 1926.601
Position flaggersFlagger struck-byTrained flaggers, signaling devices, escape routeMUTCD / OSHA 1926.201
Night/low visibilityReduced-visibility struck-byLighting, retroreflective apparel, enhanced controlMUTCD

Separation and the temporary traffic control plan

A Traffic Control and Work Zone Safety JHA succeeds on two things: the temporary traffic control plan and the separation of workers from vehicles. The traffic control plan, conforming to the MUTCD, is what warns, guides, and slows the public traffic — it is the system that gives drivers the time and information to navigate the work zone safely. The separation is what protects the workers when the traffic control is not enough, because some driver will always fail to follow it: buffer space, positive barriers, lane closures, and high-visibility apparel put distance and protection between the crew and the vehicles. The strongest control is physical separation — a closed lane or a barrier — because it does not depend on every driver doing the right thing. A JHA built on the traffic control plan plus real separation is the one that holds up.

From the field: what actually goes wrong

In fourteen years across federal, heavy civil, and industrial projects, work-zone struck-by is one of the hazards I treat with the most respect, because the deadliest part of it — the public driver — is entirely outside our control. We can set up a perfect MUTCD traffic control plan, and a speeding or distracted driver can still come through it. That reality is exactly why the control philosophy has to be separation, not just warning: cones and signs guide the drivers who are paying attention, but the buffer space, the barriers, and the lane closures are what protect the crew from the driver who is not. The more we can physically separate workers from live traffic, the less we depend on every driver doing the right thing.

The internal traffic hazard is the one that gets overlooked. Crews focus on the public traffic and forget that the equipment and trucks operating inside the work zone kill workers too — a backing dump truck, a loader swinging around, a worker on foot in an operator's blind spot. On the projects I have run, the internal traffic control plan that separates equipment from workers on foot is as important as the external one. And the flaggers deserve special attention: they stand in the struck-by zone by definition, and they need training, proper devices, high-visibility apparel, and — critically — a planned escape route for when a vehicle does not stop. The JHA that builds the traffic control plan, prioritizes separation, manages the internal traffic, and protects the flaggers is the one that brings the work-zone crew home.

The bottom line

A Traffic Control and Work Zone Safety JHA names the struck-by-traffic, the equipment, and the flagger hazards with specific controls — an MUTCD-conforming traffic control plan, real separation of workers from vehicles through buffers and barriers, an internal traffic control plan, and protected, trained flaggers. The deadliest hazard is the driver we cannot control, which is why separation beats warning. The JHA that puts distance and protection between the crew and the traffic is the one that saves lives.

Frequently asked questions

What is the deadliest work-zone hazard?

Workers on foot struck by public traffic — vehicles driven by the public at speed, outside the contractor's control. Because some driver will always fail to follow the traffic control, the controlling philosophy is separation: buffer space, positive barriers, and lane closures put distance and protection between the crew and the vehicles.

What is the difference between warning and separating traffic?

An MUTCD-conforming traffic control plan — advance warning signs, tapers, channelizing devices, speed reduction — warns and guides the drivers who are paying attention. Separation, through buffer space, barriers, and lane closures, protects the crew from the driver who is not, which is why physical separation is the stronger control.

Why does internal traffic control matter?

Construction equipment and trucks operating inside the work zone strike workers on foot too — a backing dump truck, a loader swinging around, a worker in an operator's blind spot. An internal traffic control plan that separates equipment from workers is as important as managing the public traffic.

How are flaggers protected?

Flaggers stand in the struck-by zone by definition, so they need training, proper signaling devices, high-visibility apparel, a position where they are visible, and — critically — a planned escape route for when a vehicle does not stop.


Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.