Channelizing Devices: Cones, Drums and Barricades

A cone, a drum and a Type 3 barricade. Illustration drawn by Safe Pass Traffic; not to scale.

Channelizing devices are the cones, posts, panels, drums and barricades that guide traffic through a work zone. They warn drivers of work in or near the road and steer them smoothly from one lane to another, into a narrower roadway, or onto a detour.

What it means

Chapter 6K of the California MUTCD 2026 Edition lists the channelizing devices: cones, tubular markers, channelizers (CA), portable delineators, vertical panels, drums, barricades and longitudinal channelizing devices. All of them shall be crashworthy. They also keep traffic away from the work space, pavement drop-offs, pedestrian paths, bicycle facilities and opposing traffic.

Cones (6K.03): predominantly orange. At least 18 inches tall for daytime and low-speed use; at least 28 inches on freeways and other high-speed roads, and at night on all highways. At night, cones carry retroreflective white bands; 28 to 36 inch cones use a 6-inch band 3 to 4 inches from the top and a 4-inch band about 2 inches below it.
Tubular markers (6K.04): posts with a circular cross-section, either affixed to the pavement or portable. California defines the channelizer (CA) as a special tubular marker affixed to the pavement, with a cylindrical lower part and flattened upper part, and the portable delineator as a weighted-base tubular marker.
Vertical panels (6K.05): striped panels 8 to 12 inches wide and at least 24 inches tall, with diagonal orange and white stripes sloping down toward the side traffic is to pass. Useful where space is limited.
Drums (6K.06): at least 36 inches tall and 18 inches wide, lightweight and deformable, never metal, with alternating orange and white retroreflective stripes (at least two of each, top stripe orange) and closed tops. Generally used for longer-duration work.
Barricades (6K.07): Type 1, 2 and 3 have one, two or three rails. Rails are 8 to 12 inches wide with orange and white stripes sloping down at 45 degrees toward the side traffic is to pass. Minimum length is 24 inches for Type 1 and 2, and 48 inches for Type 3.
Longitudinal channelizing devices (6K.10): lightweight, deformable units that connect together. They may replace a line of cones, drums or barricades, may be water-ballasted, and may be used for pedestrian control, where they shall be interlocked without gaps.

What drivers often get wrong

Treating cones as a suggestion. A line of devices marks where your lane now is. Stay on the traffic side of it.
Ignoring the stripe direction. On barricades and vertical panels, the stripes slope down toward the side you are supposed to pass on.
Assuming a closed lane is empty. Workers, equipment and drop-offs are often right behind the devices.

Where it goes in a work zone

Channelizing devices form the tapers in the transition area and line the buffer and work space. Their spacing should not exceed the maximums in Table 6K-101(CA), and the plan shows device type, taper lengths and spacing for each layout. Type 3 barricades typically sit at a full road closure, often carrying the ROAD CLOSED (R11-2) sign. On a lane closure, the arrow board shall be located behind the channelizing devices that move traffic out of the closed lane.

What contractors need to know

Match the device to speed, duration and time of day. Night work on any highway calls for the taller cone size, and drums are generally meant for longer-duration use.
Drums should not be weighted with sand or water in a way that becomes hazardous when struck.
Longitudinal devices used at night to channelize traffic should get retroreflective material or delineation.
Temporary traffic barriers (6K.09) are not TTC devices in themselves, but can serve as one when placed like a line of channelizing devices and properly marked.

Related signs

Frequently asked questions

How tall do traffic cones have to be in California?

At least 18 inches for daytime and low-speed use, and at least 28 inches on freeways and other high-speed roads, or at night on any highway.

What is the difference between a Type 1, 2 and 3 barricade?

The number of rails: one, two or three. Type 3 barricades are at least 48 inches long and are commonly used at road closures.

What is a channelizer (CA)?

A California-defined type of tubular marker for temporary traffic control, affixed to the pavement. It is different from the general term “channelizing devices.”

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 which devices go where and how they are spaced; your contractor or traffic control provider sets them in the field. Call or text (714) 362-1348 or request a quote.