The CA MUTCD says,
The function of channelizing devices is to warn road users of conditions created by work activities in or near the roadway and to guide road users. Channelizing devices include cones, tubular markers, channelizers (CA), portable delineators, vertical panels, drums, barricades, and longitudinal channelizing devices.
Here is the full text on channelizing devices from the CA MUTCD. Look up the original document for correct formatting.
Section 6F.63 Channelizing Devices
Standard:
01 Designs of various channelizing devices shall be as shown in Figure 6F–7 and 6F-102(CA). All channelizing devices shall be crashworthy.
Support:
02 The function of channelizing devices is to warn road users of conditions created by work activities in or near the roadway and to guide road users. Channelizing devices include cones, tubular markers, channelizers (CA), portable delineators, vertical panels, drums, barricades, and longitudinal channelizing devices.
03 Channelizing devices provide for smooth and gradual vehicular traffic flow from one lane to another, onto a bypass or detour, or into a narrower traveled way. They are also used to channelize vehicular traffic away from the work space, pavement drop-offs, pedestrian or shared-use paths, or opposing directions of vehicular traffic. Standard:
04 Devices used to channelize pedestrians shall be detectable to users of long canes and visible to persons having low vision.
05 Where channelizing devices are used to channelize pedestrians, there shall be continuous detectable bottom and top surfaces to be detectable to users of long canes. The bottom of the bottom surface shall be no higher than 2 inches above the ground. The top of the top surface shall be no lower than 32 inches above the ground.
Option:
06 A gap not exceeding 2 inches between the bottom rail and the ground surface may be used to facilitate drainage.
Guidance:
07 Where multiple channelizing devices are aligned to form a continuous pedestrian channelizer, connection points should be smooth to optimize long-cane and hand trailing.
08 The spacing between cones, tubular markers, vertical panels, drums, and barricades should not exceed a distance in feet equal to 1.0 times the speed limit in mph when used for taper channelization, and a distance in feet equal to 2.0 times the speed limit in mph when used for tangent channelization.
09 When channelizing devices have the potential of leading vehicular traffic out of the intended vehicular traffic space as shown in Figure 6H-39, the channelizing devices should be extended a distance in feet of 2.0 times the speed limit in mph beyond the downstream end of the transition area.
09a The spacing of channelizing devices should not exceed the maximum distances shown in Table 6F-101(CA). Option:
10 Warning lights (see Section 6F.83) may be added to channelizing devices in areas with frequent fog, snow, or severe roadway curvature, or where visual distractions are present.
Standard:
11 Warning lights shall flash when placed on channelizing devices used alone or in a cluster to warn of a condition. Except for the sequential flashing warning lights discussed in Paragraphs 12 and 13, warning lights placed on channelizing devices used in a series to channelize road users shall be steady-burn. Option:
12 A series of sequential flashing warning lights may be placed on channelizing devices that form a merging taper in order to increase driver detection and recognition of the merging taper.
Standard:
13 When used, the successive flashing of the sequential warning lights shall occur from the upstream end of the merging taper to the downstream end of the merging taper in order to identify the desired vehicle path. Each warning light in the sequence shall be flashed at a rate of not less than 55 nor more than 75 times per minute.
14 The retroreflective material used on channelizing devices shall have a smooth, sealed outer surface that will display a similar color day or night.
Option:
15 The name and telephone number of the highway agency, contractor, or supplier may be displayed on the nonretroreflective surface of all types of channelizing devices.
Standard:
16 The letters and numbers of the name and telephone number shall be non-retroreflective and not over 2 inches in height.
Guidance:
17 Particular attention should be given to maintaining the channelizing devices to keep them clean, visible, and properly positioned at all times.
Standard:
18 Devices that are damaged or have lost a significant amount of their retroreflectivity and effectiveness shall be replaced.
Section 6F.64 Cones
Standard:
01 Cones (see Figure 6F-7) shall be predominantly orange and shall be made of a material that can be struck without causing damage to the impacting vehicle. For daytime and low-speed roadways, cones shall be not less than 18 inches in height. When cones are used on freeways and other high-speed highways or at night on all highways, or when more conspicuous guidance is needed, cones shall be a minimum of 28 inches in height.
02 For nighttime use, cones shall be retroreflectorized or equipped with lighting devices for maximum visibility. Retroreflectorization of cones that are 28 to 36 inches in height shall be provided by a 6-inch wide white band located 3 to 4 inches from the top of the cone and an additional 4-inch wide white band located approximately 2 inches below the 6-inch band.
03 Retroreflectorization of cones that are more than 36 inches in height shall be provided by horizontal, circumferential, alternating orange and white retroreflective stripes that are 4 to 6 inches wide. Each cone shall have a minimum of two orange and two white stripes with the top stripe being orange. Any nonretroreflective spaces between the orange and white stripes shall not exceed 3 inches in width.
Support:
03a The 36 inch and 42 inch high cones provide additional conspicuity in visually complex environments and for older road users.
Option:
04 Traffic cones may be used to channelize road users, divide opposing vehicular traffic lanes, divide lanes when two or more lanes are kept open in the same direction, and delineate short duration maintenance and utility work. Guidance:
05 Steps should be taken to minimize the possibility of cones being blown over or displaced by wind or moving vehicular traffic.
Option:
06 Cones may be doubled up to increase their weight. Support:
07 Some cones are constructed with bases that can be filled with ballast. Others have specially weighted bases, or weight such as sandbag rings that can be dropped over the cones and onto the base to provide added stability. Guidance:
08 Ballast should be kept to the minimum amount needed. Option:
09 Retroreflectorization of 28 inch in height or higher cones may be provided by a 13 inch band (sleeve). Standard:
10 On State highways, the retroreflectorized bands shall be visible at 1000 feet at night under illumination of legal high beam headlights, by persons with vision of or corrected to 20/20.
Guidance:
11 On local roads, the retroreflectorized bands should be visible at 1000 feet at night under illumination of legal high beam headlights, by persons with vision of or corrected to 20/20.
Support:
12 Refer to Caltrans’ Standard Specifications Section 12-3.01A(4) for visibility criteria cited. See Section 1A.11 for information regarding this publication.
Section 6F.65 Tubular Markers
Support:
00a Tubular markers are used to guide and channelize traffic for temporary traffic control. Tubular markers generally have the same circular cross-section throughout their length. Tubular markers may be affixed to the ground or may be portable. There are three types of tubular markers and they are defined as following:
00b The term “tubular marker” is used for a tubular marker that is affixed to the pavement and is cylindrical from top to bottom 00c The term “channelizer (CA)” is a special type of tubular marker that is affixed to the pavement and has a cylindrical lower portion and a flattened upper portion. This term “channelizer (CA)” is not to be confused with the term "channelizing device(s)" in Section 6F.63. Although it is similar to the channelizer for permanent use, as discussed in Section 3H.01 and shown in Figure 3H-101(CA), there are differences. The channelizer (CA) is used for temporary traffic control.
00d The term “portable delineator” is used to describe a tubular marker that is not affixed to the pavement but stabilized by using a weighted base or weights, and is cylindrical from top to bottom. This term “portable delineator” is not to be confused with the term "delineator " in Section 6F.80.
Standard:
00e The retroreflectorized bands for tubular markers, channelizers (CA), and portable delineators shall be visible at 1000 feet during night under illumination of legal high beam headlights, by persons with vision of or corrected to 20/20.
Support:
00f Refer to Caltrans’ Standard Specifications Section 12-3.01A(4) for visibility criteria cited. See Section 1A.11 for information regarding this publication.
Tubular Marker
Standard:
01 Tubular markers (see Figure 6F-7) shall be predominantly orange and shall be not less than 18 inches high and 2 inches wide facing road users. They shall be made of a material that can be struck without causing damage to the impacting vehicle.
02 Tubular markers shall be a minimum of 28 inches in height when they are used on freeways and other high-speed highways, on all highways during nighttime, or whenever more conspicuous guidance is needed.
03 For nighttime use, tubular markers shall be retroreflectorized. Retroreflectorization of tubular markers that have a height of less than 42 inches shall be provided by two 3-inch wide white bands placed a maximum of 2 inches from the top with a maximum of 6 inches between the bands. Retroreflectorization of tubular markers that have a height of 42 inches or more shall be provided by four 4- to 6-inch wide alternating orange and white stripes with the top stripe being orange.
Support:
03a The 42 inch high tubular markers provide additional conspicuity in visually complex environments and for older road users.
Guidance:
04 Tubular markers have less visible area than other devices and should be used only where space restrictions do not allow for the use of other more visible devices.
05 Tubular markers should be stabilized by affixing them to the pavement. Option:
06 Tubular markers may be used effectively to divide opposing lanes of road users, divide vehicular traffic lanes when two or more lanes of moving vehicular traffic are kept open in the same direction, and to delineate the edge of a pavement drop off where space limitations do not allow the use of larger devices.
Standard:
07 A tubular marker shall be attached to the pavement to display the minimum 2-inch width to the approaching road users.
Portable Delineator Standard:
08 The design of a portable delineator shall be as shown in Figure 6F-102(CA). 09 Portable delineators shall be a minimum of 36 inches in height. The vertical portion of portable delineators shall be fluorescent orange or predominantly orange. The posts shall be not less than 3 inches in width or diameter. Retroreflectorization of portable delineators that have a height of less than 42 inches shall be provided by two 3-inch wide white bands placed a maximum of 2 inches from the top with a maximum of 6 inches between the bands. Retroreflectorization of portable delineators that have a height of 42 inches or more shall be provided by four 4-inch to 6-inch wide alternating orange and white stripes with the top stripe being orange.
Support:
10 The 42 inch or higher portable delineators provide additional conspicuity in visually complex environments and for older road users.
Guidance:
11 Portable delineators have less visible area than other devices and should be used only where space restrictions do not allow for the use of other more visible devices.
12 Portable delineators should be stabilized by using weighted bases, or weights such as sandbag rings that can be dropped over the portable delineators and onto the base to provide added stability. Ballast should be kept to the minimum amount needed.
Option:
13 Portable delineators may be used effectively to divide opposing lanes of road users, divide vehicular traffic lanes when two or more lanes of moving vehicular traffic are kept open in the same direction, and to delineate the edge of a pavement drop off where space limitations do not allow the use of larger devices.
Channelizer(CA) Standard:
14 When a channelizer (CA) is used, it shall be attached to the pavement in a manner such that the retroreflectorized bands facing road users meet the minimum visibility requirements.
15 The design of a channelizer (CA) shall be as shown in Figure 6F-102(CA). The height shall be 36 inch minimum where speeds are above 40 mph. The height shall be 28 inch minimum where speeds are 40 mph or less. The width of the post shall be 2 ¼ inch minimum and the color predominantly orange. Channelizers (CA) shall be affixed with retroreflective white sheeting, 3 by 12 inches in size.
Support:
16 Channelizers (CA) are implanted in the ground or affixed to the pavement, and are not susceptible to displacement, and are capable of normally withstanding numerous vehicular impacts.
17 Channelizers (CA) are generally used in series to create a visual fence/barrier, to provide additional guidance and/or restriction to traffic.
Option:
18 Channelizers (CA) may be used in lieu of cones, portable delineators, or drums, to channelize traffic or divide opposing lanes of traffic.
Section 6F.66 Vertical Panels
Standard:
01 Vertical panels (see Figure 6F-7) shall have retroreflective striped material that is 8 to 12 inches in width and at least 24 inches in height. They shall have alternating diagonal orange and white retroreflective stripes sloping downward at an angle of 45 degrees in the direction vehicular traffic is to pass.
02 Where the height of the retroreflective material on the vertical panel is 36 inches or more, a stripe width of 6 inches shall be used.
Guidance:
02a Vertical panels should be a minimum of 12 inch in width. Option:
03 Where the height of the retroreflective material on the vertical panel is less than 36 inches, a stripe width of 4 inches may be used.
04 Where space is limited, vertical panels may be used to channelize vehicular traffic, divide opposing lanes, or replace barricades.
Section 6F.67 Drums
Standard:
01 Drums (see Figure 6F-7) used for road user warning or channelization shall be constructed of lightweight, deformable materials. They shall be a minimum of 36 inches in height and have at least an 18inch minimum width regardless of orientation. Metal drums shall not be used. The markings on drums shall be horizontal, circumferential, alternating orange and white retroreflective stripes 4 to 6 inches wide. Each drum shall have a minimum of two orange and two white stripes with the top stripe being orange. Any non-retroreflectorized spaces between the horizontal orange and white stripes shall not exceed 3 inches wide. Drums shall have closed tops that will not allow collection of construction debris or other debris.
Support:
02 Drums are highly visible, have good target value, give the appearance of being formidable obstacles and, therefore, command the respect of road users. They are portable enough to be shifted from place to place within a TTC zone in order to accommodate changing conditions, but are generally used in situations where they will remain in place for a prolonged period of time.
Option:
03 Although drums are most commonly used to channelize or delineate road user flow, they may also be used alone or in groups to mark specific locations.
Guidance:
04 Drums should not be weighted with sand, water, or any material to the extent that would make them hazardous to road users or workers when struck. Drums used in regions susceptible to freezing should have drain holes in the bottom so that water will not accumulate and freeze causing a hazard if struck by a road user. Standard:
05 Ballast shall not be placed on the top of a drum.
06 On State highways, the retroreflectorized bands shall be maintained at or above minimum levels in Table 2A-3. Guidance:
07 On local roads, the retroreflectorized bands should be maintained at or above minimum levels in Table 2A-3. Support:
08 Refer to Caltrans’ Standard Specifications Section 12-3.01A(4) for visibility criteria cited. See Section 1A.11 for information regarding this publication.