Flagger Hand Signals Explained 

Road construction, utility repairs, and lane closures all rely on flaggers: workers positioned at the edge of a work zone, using a paddle, flag, or flashlight to tell drivers when to stop, when to go, and when to slow down. It’s a common sight for anyone who drives, but the standardized signals behind it aren’t always obvious to drivers passing through.

A flagger’s signal has to be unmistakable. There’s no room for a driver to guess what it means, especially when they’re moving at speed. In this clip from HeatSpring’s National Flagger Certification Training course, instructor Jenny Conrardy walks through the exact body positioning, paddle and flag handling, and free-arm gestures for stop, proceed, and slow, along with the flashlight protocol used at night.

Watch the video below, or read on for a transcript of Jenny’s full walkthrough.

Reading the signals

Flaggers stand guard between moving traffic and the workers behind them. The signals we’re about to cover are what make that job possible. We’ll walk through the flagger’s core hand signals: how to use the paddle, the flag, and the flashlight for nighttime or emergency situations.

These signs and signals aren’t just formalities. A clear, correctly executed signal is often the only thing standing between a driver and a life-threatening mistake.

We’ll break down exactly how to hold your body, your signaling device, and your free hand for each command, so there’s no ambiguity for the driver on the other end. By the end of this walkthrough, you’ll know not just what each signal looks like, but why the details, arm height, hand position, device choice, matter just as much as the signal itself.

Since the paddle is the primary device, its three gestures are the ones to be expertly familiar with. Let’s start there.

For stop: face the road users. Aim the paddle’s STOP face toward them, arm extended horizontally and stationary. The free arm goes up too, palm out, raised above shoulder level toward approaching traffic. Not just palm up, but genuinely above the shoulder so it can be seen at a distance.

For proceed: the paddle rotates to show its SLOW face. Your body pivots slightly away from traffic, and the paddle stays extended and stationary. It never hides, never waves. Instead, the free hand alone motions traffic forward by moving horizontally left to right, never going above shoulder height.

For alert or slow: the SLOW face stays up and still, with an optional up-and-down motion of the free hand, palm down, to reinforce the message. Again, never above shoulder height.

The flag’s stop posture is almost identical to the paddle. Face the road users, extend the flag staff horizontally across their lane, stationary, with the full flag hanging visibly below the staff. The free arm goes up, palm out, raised above shoulder level toward traffic, same as the paddle.

Proceed is where the flag breaks with the paddle entirely, and this is a hard rule, a “shall,” not a “may” or “should.” Flags shall never be used to signal proceed. The flag and arm lower completely out of the driver’s view, and the free hand alone does the gesturing. Your body pivots slightly away from traffic, and the free hand motions traffic forward by moving horizontally left to right, never going above shoulder height. A moving red flag reads as danger, so waving it to mean “come on ahead” sends a dangerous mixed message.

For alert or slow with the flag, sweep it slowly from shoulder level to straight down, never raising above horizontal, while the free hand stays down.

One last device is reserved for emergencies at night, at a flagger station that isn’t illuminated: the flashlight. Its red glow cone goes in the left hand while the paddle or flag stays in the right. The light supplements the primary device, it doesn’t replace it.

To stop traffic with the flashlight, extend the left arm down and sweep it in a slow arc left to right, reaching no further than 45 degrees from vertical. 

To signal proceed, hold the flag down at your side, pivot your body slightly away from traffic, point the flashlight at the vehicle’s bumper, then slowly aim it toward the open lane and hold that position. The flagger shall not wave the flashlight for proceed, because a waving light reads as an alert, not a go-ahead. Lastly, to alert or slow, hold the flag down at your side, point toward traffic, and wave the flashlight in a figure-eight motion.

Three signals, three signs. They can easily be confused under stress, which is exactly why it’s important to practice before the scenario occurs, so these movements feel second nature when the moment for action arrives.

Traffic is relying on you to be a professional and a leader. Stay safe out there.

Learn every signal, inside and out

Signals only work if they’re executed correctly, every time. HeatSpring’s National Flagger Certification Training course walks you through each one in detail, along with everything else you need to become a trained and authorized flagger.

Enroll in the National Flagger Certification course today.