How Tall Is a Jersey Barrier? Height & Dimensions

A standard jersey barrier is 32 inches tall (813 millimeters). The 32-inch height is the result of decades of crash testing under the AASHTO MASH protocol and is the modern crash-tested standard for most new MASH Test Level 3 (TL-3) installations. Two taller variants exist for specific applications: 42-inch barriers for high-speed locations or where heavy vehicle profile demands more height, and 54-inch barriers for MASH Test Level 5 (TL-5) tractor-semitrailer containment.

The barrier height is one of the geometry parameters that determines crash performance. A 32-inch F-shape at 4,000 PSI mass, with the standard 24-inch base width and 7-inch top width, produces the redirective behavior the system was crash-tested against. Cutting height shorter compromises the crash rating; adding height shifts the system to a different MASH test level.

What Is the Standard Height of a Jersey Barrier?

The default jersey barrier height across the U.S. precast market is 32 inches. The dimension is consistent across the major manufacturers (Oldcastle, Knife River, Concrete Industries, Bryan Concrete, Wausau Tile) and across both F-shape and single-slope profiles in their standard product lines. The 32-inch dimension is measured from the bottom of the barrier base to the top of the barrier face on level ground.

For F-shape barriers, the 32-inch overall height breaks down as:

• 3-inch toe at the base
• 13-inch lower slope rise
• 16-inch upper face

The toe-and-lower-slope geometry is the working part of the redirective behavior. When a vehicle strikes the barrier at an angle, the tire rides up the lower slope, transferring impact energy through tire compression and suspension deflection rather than through cabin crushing.

Why 32 Inches Specifically?

The 32-inch height came out of crash testing in the late 1970s and 1980s that refined the original New Jersey 1950s profile. Federal Highway Administration test data, summarized in the FHWA Roadside Design Guide, showed that 32 inches:

• Cleared the bumper height of typical passenger vehicles, putting the lower slope in the optimal position to engage the tire and lower body
• Stopped vehicles from vaulting over the barrier in angled impacts
• Stayed below the windshield height of typical passenger vehicles, reducing the chance of cabin intrusion during impact

Going much shorter creates vault risk. Going much taller creates visibility issues for drivers and adds material cost without improving redirective performance for the standard test vehicle. 32 inches is the geometry that balances both.

What Are the Tall Variants?

Two configurations push above 32 inches for specific applications:

When to Specify a 42-Inch Barrier

The 42-inch variant adds a 10-inch top extension to the standard 32-inch profile. Applications:

• Median locations on high-speed roads where headlight glare from oncoming traffic creates a safety concern
• Sites where heavy commercial vehicle profile (cargo vans, box trucks) at higher speeds demands more height to prevent vault
• Locations where pedestrian visibility through the barrier is undesirable (for example, areas where pedestrians at the protected side should not have direct sight lines to fast traffic)

The 42-inch barrier is uncommon on parking-lot perimeter work because parking-lot speeds are low and the standard 32-inch is sufficient. It appears more often on freeway-adjacent perimeter and on bridge approaches.

When to Specify a 54-Inch Barrier

The 54-inch MASH TL-5 barrier is engineered for tractor-semitrailer containment. The added height keeps the impacting truck's cab and trailer profile from vaulting the barrier. Applications:

• Distribution-center perimeter where tractor-semitrailer impact is foreseeable
• Freeway-adjacent commercial property where high-volume truck traffic creates the threat profile
• Industrial truck-court perimeter at sites with significant heavy-vehicle activity

A 54-inch TL-5 barrier at 10-foot length weighs about 6,400 pounds, requires a 35-ton minimum crane, and costs significantly more per linear foot than the standard 32-inch product. For most parking-lot perimeter work, TL-3 at 32 inches is the right call.

For sizing detail on the standard product, see jersey barrier dimensions and specs. For weight and lift planning, see how much does a jersey barrier weigh.

Does the Height Affect Visibility for Drivers?

Yes, and that is part of why the 32-inch standard exists. A 32-inch barrier sits below the eye line of most drivers, allowing them to see across the barrier into the perimeter beyond. A 42-inch or 54-inch barrier blocks more sight line, which is sometimes a safety feature (preventing distraction from headlight glare) and sometimes a safety concern (reducing situational awareness for drivers approaching an intersection or driveway).

For parking-lot perimeter projects, our default is 32 inches unless a specific reason exists to spec taller. The visibility trade-off is usually worth keeping the 32-inch standard.

What About the Bottom of the Barrier?

The 32-inch dimension is the height above the ground at the bottom of the barrier base. The base sits flat on the pavement, with the toe (the lowest 3 inches of the F-shape profile) directly on the pavement surface. Some configurations cast a bedding course or shim under the barrier to level the section -- when that happens, the effective height above the surrounding pavement increases by the bedding thickness.

For pour-in-place jersey barrier (cast on-site rather than precast), the dimension is measured from the slab surface to the top of the cast.

Industry Baseline Range

Current Market Reality

The 32-inch standard has been stable across the major U.S. precasters for the past 20 years and shows no signs of changing in 2026. New product development tends to focus on connection systems, surface finishes, and TL-4 hybrid designs, not on revised height standards. The 42-inch variant remains a specialty product and is not stocked at most regional plants -- expect 14- to 21-day lead times when specifying the 42-inch product. The 54-inch TL-5 is available from Concrete Industries and a handful of other large-format precasters with similar lead times.

Where We Specify Jersey Barrier Heights in Oregon

Our default for new Pacific Northwest perimeter work is the 32-inch F-shape at MASH TL-3. We move up to 42 inches for headlight-glare scenarios on high-speed perimeter and to 54 inches for distribution-center truck-court perimeter where tractor-semitrailer impact is foreseeable. For a city-specific install record, see crash barrier installation in Eugene.