Traffic cones and channelizing drums: how they guide drivers and what they cannot do
The rules, taper lengths and checks that keep work zone cones and drums working
Safety Behind the Wheel Foundation built this guide from the Federal Highway Administration’s Manual on Uniform Traffic Control Devices (MUTCD) and federal work zone rules, Occupational Safety and Health Administration (OSHA) standards, National Institute for Occupational Safety and Health (NIOSH) data and published research. Every source is listed at the end.
What cones and drums are, and why they matter
Cones and channelizing drums tell drivers where to go through planned road work. A channelizing device is a marker that guides traffic along a set path. A traffic cone is the small, light kind. A channelizing drum is the larger, barrel shaped kind. Crews set them in lines to close a lane, shift traffic or mark the edge of a work area.
NIOSH lists channelizing devices, signs, barriers, pavement markings and work vehicles as common parts of a work zone [5]. In 2022, U.S. work zones saw about 96,000 collisions, about 37,000 injuries and 891 fatal injuries [5]. The same page counts 136 pedestrian deaths and says 105 were workers [5].
This guide covers the equipment side. For how to drive through one, see our article on work zone and move over safety.
What cones and drums do, and what they cannot do
Cones and drums send a message. They say, go this way. They do not build a wall.
Part 6 of the MUTCD covers temporary traffic control. It says drivers, bicyclists and pedestrians should get clear, positive guidance as they approach and pass through a work zone [3]. It also calls for a buffer space. That is open room that separates traffic from the work area and might give an errant vehicle room to recover. An errant vehicle is one that leaves its lane by mistake. No work or storage should sit in that space [3].
Federal aid rules draw a firm line between guiding and stopping. They define positive protection as devices that contain or redirect a vehicle and pass industry crash test criteria [4]. Cones and drums are built to guide. They are not built to contain or redirect a vehicle.
Worker injury data show why that matters. A study of 3,268 OSHA accident reports from 2000 to 2022 looked at struck by incidents, which include vehicle intrusions and heavy equipment. They made up over 50% of reported construction work zone accidents and nearly 70% of related deaths [6].
A line of devices does not guarantee slow driving, either. In a driving simulator study of highway crossovers in Italy, speeds stayed above the temporary posted limits in every layout tested [7]. That study used Italian rules, so treat it as a clue only. Devices work best as one layer among several.
Comparison compiled by Safety Behind the Wheel Foundation
Guiding devices compared with positive protection
| Device | Main job | Does it stop a vehicle? |
|---|---|---|
| Traffic cone | Guides traffic. Small and light, so it is quick to place | No |
| Channelizing drum | Guides traffic. Larger, so it stands out more | No |
| Positive protection device, such as a temporary traffic barrier | Separates traffic from the work space | Built to contain or redirect vehicles [4] |
The rulebook: MUTCD, OSHA and your state
The MUTCD is the national rulebook for signs, signals, markings and other traffic control devices. Federal regulations make the MUTCD, in the version the FHWA Administrator approves, the national standard for every traffic control device on public streets, highways and bicycle trails [1]. Part 6 covers road work, utility work, maintenance and incident scenes [3].
The 11th Edition is the current one. It took effect January 18, 2024, and Revision 1 took effect March 5, 2026 [8]. States had until January 18, 2026, to adopt the national manual or keep a state manual or supplement that substantially conforms to it [9]. Ask your state transportation department which version applies on your roads.
OSHA adds a second layer for workers. Where a construction area has a hazard, OSHA requires readable traffic control signs and protective traffic control devices. The design and use of those devices, including barricades, must follow Part 6 [2]. OSHA’s highway work zone page also points to the MUTCD for setting up signs, barricades and flagging [10].
Part 6 puts responsibility for plans and devices on the public body with authority over the road. It also names owners of site roadways open to public travel, meaning roads inside a site that the public can use [3]. If your property has roads like that, ask your local road authority how the rule applies.
This table shows where the equipment topics sit in the 11th Edition. Section numbers can shift between editions.
Comparison compiled by Safety Behind the Wheel Foundation
Where work zone device topics sit in the MUTCD
| Topic | Where to look | What it covers |
|---|---|---|
| Plans and tapers | Chapter 6B | Traffic control plans, work zone areas and tapers [3] |
| Worker safety | Chapter 6C | Training, barriers, speed management and high visibility clothing [3] |
| Cones, drums and similar devices | Chapter 6K | Cones, tubular markers, vertical panels, drums and barricades [11] |
| Barriers and crash cushions | Chapter 6M | Positive protection, temporary barriers and crash cushions [11] |
| Arrow boards and message signs | Chapter 6L | Portable message signs, arrow boards and flagger assistance devices [11] |
How crews use cones and drums: plans and tapers
Every setup starts with the plan, not the devices. Part 6 says planned work that affects road users should have a temporary traffic control plan, or TTC plan. That planning should be finished before crews move in, and it applies to road construction, utility jobs, maintenance and incident response, including minor ones [3].
Cones and drums do much of their work in the transition area, where traffic moves out of its normal path. Part 6 requires drivers to be steered onto the new path with suitable channelizing devices or other methods [3].
Tapers: the line that moves traffic over
A taper is a series of devices, sometimes with pavement markings, that moves traffic out of or back into its normal path [3]. Part 6 describes five kinds.
- A merging taper brings two lanes into one. It needs the longest distance [3].
- A shifting taper moves traffic sideways. It should be about half as long [3].
- A shoulder taper helps where a closed shoulder could be mistaken for a lane. It should be about one third as long [3].
- A downstream taper sits past the work space and shows that the lane is open again. It runs 50 to 100 feet, with devices about 20 feet apart [3].
- A one lane, two way taper is used where traffic takes turns on one lane. It also runs 50 to 100 feet, with devices about 20 feet apart [3].
Part 6 gives a formula for the full merging taper length, called L. It uses the width of the shift in feet (W) and the speed in miles per hour (S). At 40 mph or less, L equals W times S times S, divided by 60. At 45 mph or more, L equals W times S [3]. The speed can be the posted limit, the off peak 85th percentile speed before work began, or the speed drivers are expected to travel [3]. The 85th percentile speed is the speed that 85 of every 100 drivers stay at or below.
Using those formulas, closing one 12 foot lane at 55 mph calls for a merging taper of about 660 feet. At 35 mph, the same closure calls for about 245 feet [3]. Part 6 also warns that very long tapers can lead to slow driving and late lane changes [3]. Spacing for merging, shifting and shoulder tapers comes from the traffic control plan and the agency’s drawings.
A typical setup routine
The plan always comes first. A careful crew then tends to work in this order.
- Get the traffic control plan and read it before loading the truck.
- Walk the site and compare it with the plan. Note curves and sight lines.
- Check each cone and drum for cracks, fading, dirt and loose parts.
- Set the advance warning signs first, so drivers have notice before the taper.
- Build the taper to the planned length, working from the warning end toward the work space.
- Drive the approach as a motorist would, by day and again at night. Fix anything confusing.
- Write down the setup and who will inspect it, and when.
Choosing devices and where to get them
Devices on public roads must be chosen, designed and placed by the authorized road agency or by a qualified crew working under its approval. Residents should never set out their own devices on a public road.
Road contractors, utility crews, maintenance teams, towing firms and event operators get devices from three common channels: traffic control suppliers, equipment rental firms and qualified traffic contractors. An event organizer who needs a street closure should ask the local authority what approval is needed first.
Match the device to the job. Cones suit short jobs, quick moves and slower roads. Drums are bigger and show up from farther away, so crews often choose them for longer jobs or faster roads.
How a device behaves when a vehicle hits it also matters. Part 6 says various sections require certain traffic control devices and their supports to be crashworthy [3]. FHWA says crash testing is how it judges that quality in roadside safety hardware, and it lists work zone devices as one hardware type [12]. Ask for the test records that apply to the exact model you plan to buy.
Keeping devices working: day and night checks and removal
A setup that looked right at 8 a.m. may look wrong at 8 p.m. Part 6 says routine day and night inspections should be done. It also says people whose actions affect work zone safety should get training that fits their job [3]. Safety Behind the Wheel Foundation urges every crew to make those day and night checks routine.
Part 6 notes that reduced visibility at night affects both drivers and workers, and that impaired or tired drivers may be more common after dark [3]. A study of work zone intrusion collisions in Texas from 2020 to 2024 found that night lighting and weather affected how severe the injuries were [13].
Removal matters as much as setup. Part 6 says devices should come down as soon as practical after they stop being needed [3]. Devices left behind teach drivers to ignore them. On federal aid highway projects, each agency must carry out quality guidelines to keep devices in good shape for the length of the project [4].
When cones are not enough: protecting workers
Cones and drums mark a path. They do not protect a person standing in it. Federal aid rules set a floor. Where speeds are expected to be high and workers cannot get away from intruding traffic, agencies shall use positive protection devices unless an engineering study determines otherwise [4]. An engineering study is a documented review by qualified staff. The rule applies to Federal aid highway projects and is encouraged elsewhere [4]. States must have their policy in place by December 31, 2026 [4].
Part 6 lists other steps. These include temporary traffic barriers along the work space, lower traffic speeds, plans that limit backing by work vehicles, and a hazard assessment by a trained person. For moving jobs such as pothole patching, a shadow vehicle with lights and warning signs may shield workers [3]. Part 6 also requires workers in the zone to wear high visibility apparel that meets Performance Class 2 or 3 of the ANSI/ISEA 107 standard [3].
Common mistakes to avoid
- Cones alone on fast roads. If workers have no escape route, cones are not enough [4].
- A taper that is too short or too long. Match it to the speed [3].
- Equipment stored in the buffer space. That space should stay open [3].
- Devices left after the work ends. They should come down as soon as practical [3].
What drivers, neighbors and local officials can do
Slow down well before the first sign. Merge early and keep a gap behind the vehicle ahead. Never steer through or over cones to save time. If a device has fallen into a lane, do not stop in traffic to fix it.
If you see missing, tipped or confusing devices, tell the road owner. That is usually the state transportation department, the county or the city public works office. Give the road name, direction of travel and nearest cross street. Call 911 for a hazard that is happening now.
Local officials, school board members and small employers can ask a road agency or contractor:
- Who prepared the traffic control plan, and what speed did it use for the taper?
- Who checks the devices at night, and how often?
- How long will the setup stay, and who removes it?
- Are workers protected by more than cones if traffic is fast?
Our safer road design guide explains how to ask a road owner for a review.
Frequently asked questions
Does a work zone have to use cones or drums?
Not by name. OSHA requires that construction work areas be protected by traffic control devices that follow Part 6 of the MUTCD [2]. Part 6 covers many device types, including cones, drums and barricades [11]. The traffic control plan picks the mix that fits the road, the speed and the job. Ask the agency or contractor to show it.
Can I set out cones to close a public street for an event or a repair?
Check first. On public streets, the national standard covers every traffic control device installed there [1]. Part 6 puts responsibility for plans and devices on the public body with authority over the road [3]. Ask your city, county or state road agency what approval you need.
Will a cone or a drum stop a car?
No. These devices guide drivers. Federal rules reserve the term positive protection for devices that contain or redirect a vehicle and pass crash tests [4]. Where workers cannot get away from fast traffic, agencies must use that kind of protection unless an engineering study says otherwise [4].
How far apart should cones be in a taper?
It depends on the taper and the plan. Part 6 gives about 20 feet between devices for downstream tapers and one lane, two way tapers [3]. For other tapers, crews follow the traffic control plan and agency drawings. Speed, device type and job length all play a part, so a guess from memory is not enough.
What should I do if I see a missing or knocked over device?
Do not stop in a travel lane or walk onto the road to fix it. When it is safe, report it to the road owner with the location and direction of travel. Call 911 for immediate danger. A gap in a taper can let traffic drift toward workers, so a quick report matters.
The bottom line
Recommendation from Safety Behind the Wheel Foundation
Safety Behind the Wheel Foundation urges road agencies and crews to treat cones and drums as guides, not shields, and to add stronger protection where traffic is fast. Cones and channelizing drums are simple tools with an important job. They tell drivers where to go. They work only when the plan is sound, the taper fits the speed, the devices are in good shape and drivers pay attention.
They cannot stop a vehicle. Where traffic is fast and workers have nowhere to go, the plan needs stronger protection.
Related articles
- Work zone and move over safety: protect road crews, responders and you
- Safer road design: a field guide to the safety fixes on your street
- Night driving safety: how to see hazards and stop in time after dark
- Move over laws by state: who's protected and what you must do
- Workplace motor vehicle safety program: a step by step employer guide
Sources and further reading
- 1Electronic Code of Federal Regulations (eCFR). 23 CFR 655.603 Standards. Current as of October 2, 2026. ecfr.gov/current/title-23/section-655.603
- 2Electronic Code of Federal Regulations (eCFR). 29 CFR Part 1926 Subpart G, Signs, Signals, and Barricades (sections 1926.200 and 1926.201). Current as of October 2, 2026. ecfr.gov/…/subpart-G
- 3Federal Highway Administration (FHWA). Manual on Uniform Traffic Control Devices for Streets and Highways, 11th Edition, Part 6: Temporary Traffic Control. Published December 2023. mutcd.fhwa.dot.gov/pdfs/11th_Edition/part6.pdf
- 4Electronic Code of Federal Regulations (eCFR). 23 CFR Part 630 Subpart K, Temporary Traffic Control Devices. Current as of September 28, 2026. ecfr.gov/…/subpart-K
- 5National Institute for Occupational Safety and Health (NIOSH), CDC. Highway Work Zone Safety. Updated November 6, 2024. Data year: 2022. cdc.gov/niosh/motor-vehicle/highway/index.html
- 6Khan M, Gbiengu P, Ibrahium A, Nnaji C. Investigating patterns and causes of struck-by accidents in roadway construction projects. International Journal of Occupational Safety and Ergonomics, 2025;31(4):1225-1246. PubMed record. Data year: 2000 to 2022 (OSHA accident reports). pubmed.ncbi.nlm.nih.gov/40459033
- 7Domenichini L, La Torre F, Branzi V, Nocentini A. Speed behaviour in work zone crossovers. A driving simulator study. Accident Analysis & Prevention, 2016;98:10-24. PubMed record. pubmed.ncbi.nlm.nih.gov/27676242
- 8Federal Highway Administration (FHWA). Manual on Uniform Traffic Control Devices (MUTCD). Home page, reviewed October 2026. mutcd.fhwa.dot.gov
- 9Federal Highway Administration (FHWA). Information by State, MUTCD State Adoption. Reviewed October 2026. mutcd.fhwa.dot.gov/…/index.htm
- 10Occupational Safety and Health Administration (OSHA). Highway Work Zones and Signs, Signals, and Barricades – Overview. Reviewed October 2026 (no update date shown). osha.gov/highway-workzones
- 11Federal Highway Administration (FHWA). Manual on Uniform Traffic Control Devices, 11th Edition, Cover and Table of Contents. Published December 2023. mutcd.fhwa.dot.gov/…/11thcovtoc.pdf
- 12Federal Highway Administration (FHWA). Reduce Crash Severity. Updated March 12, 2025. highways.dot.gov/…/reduce-crash-severity
- 13Chowdhury TI, Starewich M, Barua S, Tusti AG, Das S. Impact assessment of contributing factors in direct-impact work zone crashes using heterogeneity and constrained-based discrete choice models. Accident Analysis & Prevention, 2026;231:108485. PubMed record. Data year: 2020 to 2024 (Texas crash data). pubmed.ncbi.nlm.nih.gov/41806800
This article reflects the safety priorities of work zone safety and protecting road crews and drivers. It is general education, not legal or engineering advice, and it does not replace the plan, standards or permits for a specific job. Rules change, so verify details with official sources. For your own situation, contact your state or local road agency, an OSHA area office or a qualified traffic control contractor. Reviewed October 2026.
Cite this article: Safety Behind the Wheel Foundation. “Traffic cones and channelizing drums: how they guide drivers and what they cannot do.” drivewithcare.org, https://drivewithcare.org/traffic-cones-channelizing-drums-work-zones/. Reviewed October 2026.
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