STOP/SLOW Paddle (R1-1 / W20-8): How It Works

STOP face (R1-1) and SLOW face (W20-8) of a flagger paddle. Illustration drawn by Safe Pass Traffic; not to scale.

The STOP/SLOW paddle is the hand-held sign a flagger uses to control traffic in a work zone. One side is a red STOP octagon (R1-1), the other an orange SLOW diamond (W20-8). STOP means stop and wait; SLOW means proceed carefully when the flagger waves you on.

What it means

Section 6D.02 of the California MUTCD 2026 Edition says the STOP/SLOW paddle should be the primary and preferred hand-signaling device, because it gives road users more positive guidance than red flags. Flags are limited to emergency situations. The paddle shall be octagonal on a rigid handle and shall be retroreflectorized when used at night. Flashing lights may be added to the faces.

The STOP face is 18 by 18 inches per Table 6G-1, and a 24 by 24 inch face may be used where greater emphasis is needed and speeds are 30 mph or higher. When the paddle is mounted on a rigid staff, the bottom of the sign should ideally be about 6 feet above the pavement. STOP/STOP or SLOW/SLOW paddles are allowed in certain situations.

What drivers often get wrong

Rolling forward on STOP. Under Section 6D.05, to stop traffic the flagger faces road users, holds the STOP face stationary with the arm extended away from the body, and raises the free hand, palm toward approaching traffic, above shoulder level. Stop and stay stopped.
Going at full speed on SLOW. To release traffic, the flagger shows the SLOW face and motions with the free hand. SLOW means proceed with caution, often past workers or in a shared single lane.
Following the car ahead instead of the flagger. The flagger may stop you even if the vehicle in front was released. Watch the paddle, not the traffic.
Treating a hand wave as a valid signal. In one-lane, two-way operations, hand movements alone are prohibited for controlling traffic, except by emergency responders or uniformed police.

Where it goes in a work zone

The paddle is held by a flagger at a flagger station, usually at each end of a one-lane, two-way section described in Chapter 6E. Drivers approaching the station should first pass advance warning signs such as ROAD WORK AHEAD (W20-1), ONE LANE ROAD (W20-4), BE PREPARED TO STOP (W3-4) and the Flagger sign (W20-7). The flagger station location, the advance signs and their spacing are shown on the approved traffic control plan.

What contractors need to know

Use paddles that meet the octagonal shape, size and night retroreflectivity rules in Section 6D.02. Consider the larger face on higher-speed approaches.
Automated Flagger Assistance Devices (AFADs), covered in Sections 6L.02 to 6L.04, are an alternative device operated by a flagger. One type uses a remotely controlled STOP/SLOW sign.
Show every flagger station and its advance signing on the plan, for each approach. The permitting agency may also have its own flagging requirements.
For a fuller overview of flagging procedures, see our guide to flagging in California.

Related signs

Frequently asked questions

What does SLOW on a flagger paddle mean?

It means you may proceed, carefully, when the flagger motions you ahead. Keep your speed down and watch for workers, equipment and oncoming traffic.

Can a flagger use a red flag instead of a paddle?

In California, the paddle should be the primary and preferred device. Red flags are limited to emergency situations under Section 6D.05.

How big is a STOP/SLOW paddle?

The STOP face is 18 by 18 inches. A 24 by 24 inch face may be used where more emphasis is needed and speeds are 30 mph or higher.

Sources

Need this sign on a traffic control plan?

Safe Pass Traffic prepares PE & TE stamped traffic control plans, striping plans and typical plans for projects statewide in California, and helps with the permit submittal. We draw the plan that shows the flagger stations and advance signs; your contractor or traffic control provider supplies the flaggers and sets the signs in the field. Call or text (714) 362-1348 or request a quote.