- A crash rated barrier has stopped a test vehicle of a set weight at a set speed in a full scale crash test.
- In the United States, crash ratings come from ASTM F2656/F2656M. A rating such as M50 P1 names the test vehicle, the impact speed and how far the vehicle got past the barrier.
- M30, M40 and M50 are a 15,000 lb medium duty truck at 30, 40 and 50 mph. Current editions grade penetration from P1 to P3, and P1 is the best.
- K4, K8 and K12 are older Department of State ratings that line up with M30, M40 and M50 at P1, but they are not interchangeable with current ASTM results.
A crash rated barrier is one that has stopped a test vehicle of a known weight at a known speed in a full scale crash test, with the distance the vehicle traveled past the barrier measured and recorded. In the United States that test is ASTM F2656/F2656M. Its ratings read like M50 P1: the letter is the test vehicle, the number is the impact speed in miles per hour, and the P rating is how far the vehicle penetrated.
What Does Crash Rated Mean for a Vehicle Barrier?
Crash rated means the barrier has passed a full scale crash test, not a calculation. The barrier and its foundation are built, a vehicle is driven into them at a controlled speed, and the penetration is measured. The rating belongs to that tested configuration.
"Crash rated" on a submittal should point to a test report for the configuration being supplied. "Designed to meet", "engineered to" and "equivalent to" describe a calculation or an opinion, not a crash rating.
How Do You Read an ASTM F2656 Crash Rating?
An ASTM F2656 rating has two parts: the test vehicle and speed, then the penetration. The standard is ASTM F2656/F2656M, Standard Test Method for Crash Testing of Vehicle Security Barriers, now in its 2023 edition, and it covers barriers such as bollards, wedges, gates, cable barriers and crash rated fence.
- Vehicle and speed: a letter code for the test vehicle followed by the impact speed in miles per hour. M50 is a medium duty truck at 50 mph.
- Penetration: a P rating for how far the vehicle traveled past the barrier. P1 is the shortest distance and the best result.
Put together, M50 P1 means a 15,000 lb medium duty truck hit the barrier at 50 mph and penetrated 1 m (3.3 ft) or less.
What Vehicles Does ASTM F2656 Test With?
ASTM F2656 tests with six vehicles, from a small car to a heavy goods vehicle. Most security specifications in the United States call for the M vehicle, the medium duty truck.
| Code | Test vehicle | Test weight | Rated speeds |
|---|---|---|---|
| SC | Small passenger car | 2,430 lb (1,100 kg) | 30, 40, 50, 60 mph |
| FS | Full size sedan | 4,630 lb (2,100 kg) | 30, 40, 50, 60 mph |
| PU | Pickup truck | 5,070 lb (2,300 kg) | 30, 40, 50, 60 mph |
| M | Medium duty truck | 15,000 lb (6,800 kg) | 30, 40, 50 mph |
| C7 | Class 7 cabover truck | 15,873 lb (7,200 kg) | 30, 40, 50 mph |
| H | Heavy goods vehicle | 65,000 lb (29,500 kg) | 30, 40, 50 mph |
What Do M30, M40 and M50 Mean?
M30, M40 and M50 are the same 15,000 lb truck at 30, 40 and 50 mph. The speed matters more than it looks, because the energy the barrier has to absorb rises with the square of the speed. An M50 impact carries about 2.8 times the energy of an M30 impact with the same truck.
| Rating | Test vehicle and speed | Energy compared with M30 |
|---|---|---|
| M30 | 15,000 lb truck at 30 mph (about 48 km/h) | Baseline |
| M40 | 15,000 lb truck at 40 mph (about 64 km/h) | About 1.8 times |
| M50 | 15,000 lb truck at 50 mph (about 80 km/h) | About 2.8 times |
The speed to specify comes from how fast a vehicle can actually reach the barrier, which is why a vehicle approach analysis comes before the rating is chosen.
What Do the P1, P2 and P3 Penetration Ratings Mean?
The P rating records how far the vehicle traveled past the barrier, which tells the designer how much clear distance the site needs behind it. Current editions of ASTM F2656 use three ratings.
| Rating | Penetration | What it means |
|---|---|---|
| P1 | 1 m (3.3 ft) or less | The vehicle is stopped at the barrier line. The highest performance rating. |
| P2 | 1.01 to 7 m (3.31 to 23.0 ft) | The vehicle travels a short, controlled distance past the barrier. |
| P3 | 7.01 to 30 m (23.1 to 98.4 ft) | Greater penetration. Suitable only where the standoff behind the barrier allows it. |
The 2007 edition also had a P4 rating for 30 m (98.4 ft) or more. Later editions dropped it, and P4 results are not accepted on the DoD Anti Ram Vehicle Barrier List.
Where penetration is measured from has also changed. From the 2019 edition on, it is measured from the leading edge of the barrier element that was hit. Earlier editions measured from the trailing edge, the back of the barrier, so check which edition a test report was written to before comparing results.
What Is a K Rating and How Does It Compare to ASTM F2656?
A K rating is the older Department of State crash rating for a 15,000 lb truck: K4 at 30 mph, K8 at 40 mph and K12 at 50 mph. It comes from SD STD 02.01, first issued in 1985, which paired each K rating with an L rating for penetration, so a barrier might be listed as K12 L3. The 2003 revision dropped the L ratings and required penetration of 1 m or less for every K rating.
ASTM F2656 was first published in 2007 and is now the standard US specifications cite. K ratings still appear in older specifications, and the DoD list still includes barriers tested to the Department of State standard. They line up with ASTM ratings as follows:
| K rating | Test vehicle and speed | Closest ASTM rating | Penetration limit |
|---|---|---|---|
| K4 | 15,000 lb truck at 30 mph | M30 P1 | 1 m (3.3 ft) |
| K8 | 15,000 lb truck at 40 mph | M40 P1 | 1 m (3.3 ft) |
| K12 | 15,000 lb truck at 50 mph | M50 P1 | 1 m (3.3 ft) |
The ratings correspond, but they are not interchangeable. The Department of State standard measured penetration from the back of the barrier, as ASTM did until 2019. Current ASTM editions measure from the front of the barrier element that was hit, so a K12 result and a current M50 P1 result are not the same measurement. On a new US project, specify the ASTM rating and treat a K rating as a historical reference.
Why Specify ASTM F2656 Tested Barriers on US Projects?
ASTM F2656 is the crash test standard that US federal, state and CSI format specifications cite most often. It is a consensus test method written under ASTM rules that keep producers from outvoting the people who use their products.
ASTM does not test, certify or approve products. The evidence of a crash rating is the test report itself, which documents the barrier, its foundation, the vehicle, the impact speed and the measured penetration. That is the document to ask for.
The current DoD Anti Ram Vehicle Barrier List (September 2026) includes barriers certified to ASTM F2656 or previously tested to the Department of State standard. For US projects, specify the ASTM F2656 rating first.
How Do You Specify a Crash Rated Barrier?
Specify the vehicle, speed and penetration the site needs, and require the test report that proves it. Five points cover most specifications:
- Set the vehicle and speed from the site: base the M rating on a vehicle approach analysis by a qualified engineer, not on the highest rating available.
- Set the penetration from the standoff: choose P1 where the asset is close to the line and allow P2 where the distance supports it.
- Ask for the test report: require the ASTM F2656 report for the configuration being supplied, including the edition it was tested to, the foundation, footing depth and connections.
- Reject equivalence claims: "designed to meet" or "equivalent to" a rating is not a crash rating.
- Check the whole line: a crash rated barrier with an untested gate or termination is only as strong as the weakest point.
BSP rates its barriers from 30+ full scale crash tests to ASTM F2656, across M30 and M50 at P1 and P2, with qualifying configurations on the DoD Anti Ram Vehicle Barrier List. See the Standards page for how BSP documents its ratings, browse passive vehicle barriers such as anti ram bollards and the passive cable barrier, or active vehicle barriers such as wedge barriers. For more on why the test matters, read why crash testing matters for vehicle barriers.
Crash Rating FAQs
What does M50 P1 mean?
M50 means a 15,000 lb medium duty truck at 50 mph. P1 means the truck penetrated 1 m (3.3 ft) or less past the barrier. Together they describe the highest M rating with the shortest penetration.
What is a K12 barrier?
A K12 barrier stopped a 15,000 lb truck at 50 mph under the former Department of State standard, with penetration limited to 1 m since its 2003 revision. M50 P1 is the closest ASTM F2656 rating.
Is a K12 rating the same as M50 P1?
They are close but not the same. Both use a 15,000 lb truck at 50 mph with a 1 m penetration limit, but current ASTM editions measure penetration from the front of the barrier element that was hit, while the Department of State standard measured from the back. Specify M50 P1 on new US projects.
What is the difference between P1 and P2?
P1 means the vehicle penetrated 1 m (3.3 ft) or less. P2 means it penetrated between 1.01 and 7 m (3.31 to 23.0 ft). P1 suits sites with little standoff, and P2 can work where there is room behind the barrier.
What happened to the P4 penetration rating?
P4 covered penetration of 30 m (98.4 ft) or more in the 2007 edition of ASTM F2656. Later editions dropped it, and P4 results are not accepted on the DoD Anti Ram Vehicle Barrier List.
Does ASTM certify crash rated barriers?
No. ASTM writes the test method but does not test, certify or approve products. The proof of a crash rating is the ASTM F2656 test report for the configuration being supplied, including its foundation.
Need a Crash Rated Barrier Matched to Your Site?
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