A highway cone is a 28-inch or 36-inch fluorescent-orange traffic cone with two reflective collars, weighted to 7-10+ lb, and rated for use on roadways with posted speeds of 45 mph or higher. The MUTCD calls them "channelizing devices," and what makes a cone "highway-grade" rather than a parking-lot cone is a specific combo of height, mass, and ASTM-rated reflective sheeting. Below: the rules, the sizes, and what NJ contractors should keep on the truck.
What makes a cone a "highway" cone
The MUTCD (Manual on Uniform Traffic Control Devices, 11th edition) sets minimums for cones used on roadways. The short version:
- Height: minimum 28" for low-speed roadways, minimum 36" for "high-speed and/or freeways" (interpreted as 45 mph and up).
- Color: fluorescent orange or fluorescent yellow-green for daytime visibility.
- Reflectorization for nighttime use: one 6" white retroreflective collar on a 28" cone, or one 6" plus one 4" collar on a 36" cone.
- Mass: enough that the cone resists being blown over by truck wash. Practically, 7 lb minimum for 28" and 10-12 lb for 36" highway use.
A 28" cone with no collars is a parking-lot cone. A 28" cone with one 6" collar is a highway cone for low-speed work. A 36" cone with both collars is the standard for state-route and freeway work zones. If your cone does not have collars, it is not a highway cone - period.
The size and weight matrix
| Cone | Speed limit | Reflective collars | Typical weight | Use case |
|---|---|---|---|---|
| 18" | Off-road only | None required | 3 lb | Parking lots, indoor only - NOT highway |
| 28" | Up to 40 mph | One 6" white collar | 7 lb | Local roads, residential closures, low-speed work zones |
| 28" | Up to 40 mph | One 6" white collar | 10 lb | Same job, windier conditions / truck wash |
| 36" | 45 mph and up | One 6" + one 4" collar | 10 lb | State routes, freeways, NJDOT travel-lane work |
| 36" | 55+ mph / sustained wind | One 6" + one 4" collar | 12 lb | Turnpike, Parkway, I-95, GSP work zones |
For NJ contractors: the 36" / 10 lb cone is the practical default for any job on a state route or higher. The 28" / 7 lb is fine for cul-de-sac, parking-lot, or driveway work. We do not recommend 18" cones for any roadway use - they fly the moment a Class 8 truck passes.
Reflective sheeting types - Type III vs Type IV vs Type V
The collar on a highway cone is reflective sheeting laminated onto a vinyl sleeve. ASTM D4956 grades the sheeting by retroreflectivity (how much light bounces back per square foot at a given angle). The three grades you will see:
- Type III (high-intensity prismatic, "HIP"): OK for 28" cones on local roads. ~250 candela/lux.
- Type IV (high-intensity prismatic, brighter): now standard on most 36" cones. ~500 candela/lux.
- Type V or "diamond grade": highest retroreflectivity, often spec'd for freeway work zones at NJDOT request. ~800+ candela/lux.
NJDOT specs typically require Type IV minimum on any cone used on a state route. Always check the spec sheet on the cone - the sheeting grade is a printed line, not a marketing claim.
How highway cones differ from parking cones
Three real differences:
- Mass. A parking cone is 3-5 lb. A highway cone is 7-12 lb. The extra mass is in a thicker rubber base, not the cone body. This is what keeps the cone planted when a tractor-trailer passes at 70 mph.
- PVC vs. rubber. Parking cones are usually PVC (lighter, cracks below freezing). Highway cones are PVC body with a recycled rubber base, or fully rubber/PE for cold-weather use. Rubber bases survive cold storage in a yard; PVC cracks.
- Reflective collars. Parking cones rarely have collars. Highway cones always do. If you cannot see two reflective bands when the cone is in your hand, do not put it on a state road.
How many highway cones for a typical job
MUTCD taper spacing depends on speed and lane width. The rough numbers for a single travel-lane closure on a 12-ft lane:
- 35 mph road: 7 cones in the taper, then 1 cone every 35 ft through the work zone.
- 45 mph road: 9 cones in the taper, then 1 cone every 45 ft.
- 55 mph road: 11 cones in the taper, then 1 cone every 55 ft.
- 65 mph (Turnpike, GSP): 13 cones in the taper, then 1 cone every 65 ft.
For a 1,000 ft work zone on a 55 mph state route, you need roughly 11 (taper) + 18 (length) + 6 (downstream taper) = ~35 cones. Round up to 50 to allow for damage replacement and lateral channelizing. For a step-by-step calculator, see our lane-closure cone count guide or run the job through the work-zone planner.
NJDOT and Turnpike-specific rules
NJDOT's standard work-zone spec (referenced in the NJDOT Standard Specifications for Road and Bridge Construction, Section 159) requires:
- 36" cones on all state routes with posted speed 45+ mph.
- ASTM D4956 Type IV or higher reflective sheeting on the collars.
- Cones replaced when fluorescent orange has faded to a "weak orange" (subjective - but inspectors will flag bleached cones).
- No cones with cracked bases, missing collars, or oil/tar contamination.
NJ Turnpike Authority (NJTA) work zones often require an additional spec on top of NJDOT - typically Type V sheeting and 12 lb minimum mass. Always check the contract documents before mobilizing on Turnpike or Parkway work; the rejection rate for non-compliant cones is high and costs you a day of crew time.
What to keep on the truck
A typical NJ road-work crew should carry:
- 40x 36" / 10 lb cones with Type IV collars (the daily driver).
- 10x 28" / 7 lb cones for back-of-yard and lower-speed jobs.
- 6x cone bars or cone-mounted signs for the taper head.
- A cone caddy or rack on the truck (saves 15 min on every set/strike).
- Replacement collars in 6" and 4" lengths - they peel before the cone wears out.
Where to buy highway cones in NJ
Browse our cones and channelizers category for 28" and 36" highway-rated cones with Type III, IV, and V collars. For a per-job recommendation that accounts for taper length, speed limit, and shoulder geometry, run the spec through our AI gear assistant or request a quote - same-day Central NJ delivery, NJDOT-compliant cones in stock.