Mr. Owen S. Denman, P.E.

President

Barrier Systems, Incorporated

180 River Road

Rio Vista, California 94571-1208

Dear Mr. Denman: 

In June 2000, the Federal Highway Administration accepted your Reactive Tension System 

(RTS) using either steel-clad or concrete Quickchange Moveable Barrier (QMB) segments as a 

longitudinal traffic barrier at the National Cooperative Highway Research Program (NCHRP) 

Report 350 test level 3 (TL-3). This acceptance was based on tests conducted on straight 

sections of barrier anchored at both ends but otherwise free to deflect upon impact. The 

reported dynamic deflections were 700 mm for the Steel QMB units and 610 mm for the 

Concrete QMB units. 

To reduce deflection further, you tested a Concrete QMB system, again anchored at both ends, 

but backed by a steel angle iron bolted to a simulated bridge deck 12 inches behind the field 

side of the barrier. Twenty-foot lengths of 3-inch x 4-inch x 1⁄2-inch thick angle iron were 

attached to the simulated concrete deck through the 3-inch leg of the angle with 3⁄4-inch 

diameter x 8-inch long threaded anchor rods on 2-foot centers set in epoxy to a depth of six 

inches. The 4-inch leg of the angle was vertical and faced the backside of the barrier. To 

quantify the effectiveness of this treatment, you included with your February 23, 2005, letter, 

copies of a test report prepared by Safe Technologies, Incorporated entitled “Barrier Systems, 

Incorporated, Concrete Reactive Tension System – Quickchange Moveable Barrier, 

(RTS-QMB) – Limited Deflection Test” which described the impact of a pickup truck at a 

nominal impact speed of 100 km/h and at a 25-degree angle into a concrete RTS-QMB system 

installed with the steel angle described above installed 12 inches behind the barrier proper. 

Enclosure 1 shows the test installation. In this test, the barrier was anchored at both ends and 

its dynamic deflection was reported as 473 mm. A summary of the test results is shown as 

Enclosure 2. As noted therein, all NCHRP Report 350 evaluation criteria for a TL-3 barrier 

were satisfied. 

Based on the information you provided, I concur that the RTS-QMB barrier, with a steel angle 

iron backup installed as described above, continues to meet the evaluation criteria for a TL-3 

400 Seventh St., S.W. 

Washington, D.C. 20590

In Reply Refer To: HSA-10/B-69B 

March 22, 2005 
2

barrier and exhibits less dynamic deflection than the barrier without restraint. To remain fully 

effective along its entire length, the installation must be anchored at both ends as per your 

recommendations. 

Sincerely yours, 

 

 /Original Signed by/ 

John R. Baxter, P.E. 

 Director, Office of Safety Design 

 Office of Safety 

2 Enclosures 
Barrier Systems, Inc. 

RTS-QMB Longitudinal Barrier 

STI Project: 

Limited Deflection 

RTS 

 Page 38 of 42 

 

 

Appendix F 

Figure F-1 
Barrier Systems, Inc. 

RTS-QMB Longitudinal Barrier 

STI Project: 

Limited Deflection 

RTS 

 Page 12 of 42 

Figure 1. Summary of Results-Test #QBD08 

t=0.000 sec t=.100sec t=.200sec t=.300sec t=.500sec t= .600sec

General Information Exit Conditions

 Test Agency................................................ SAFE TECHNOLOGIES, INC. Speed (km/h)................................................73.9 km/h

 Test Designation.......................................... NCHRP Report 350 Test 3-11 Angle (deg)...................................................13 Test No...................................................... QBD08 Occupant risk Values Date.......................................................... 1/18/2005 Impact Velocity (m/s)

Test Article x-direction.............................................7.4

 Type.......................................................... Barrier Systems, Inc. y-direction.............................................-4.6

18" CRTS/QMB Longitudinal Barrier Ridedown Acceleration (g's)

Installation Length....................................... 74 meters overall x-direction.............................................-7.9

 Size and/or dimension and material y-direction.............................................12.3 of key elements........................................... CRTS Section length 1000mm, height 813mm, THIV (km/h).......................................... 29.5

width 610mm, mass 726 kg. PHD (g's)....................................................12.8

Test Vehicle ASI......................................................... 1.1

 Type.........................................................Production Model Test Article Deflection (mm)

 Designation................................................2000 kg Dynamic...................................................611

 Model....................................................... 1988 Chevrolet 3/4 Ton Pick-up Permanent................................................473 Mass (kg) Vehicle Damage Curb.....................................................1983 Exterior

 Test Inertial........................................... 1993 VDS......................................................LFQ-4

 Dummy(s)............................................. n/a CDC......................................................11FLEE3 Gross Static.......................................... 1993 Interior

 OCDI...................................................LF0002000

Impact Conditions Post-Impact Vehicular Behavior (deg-gyro @ c.g.)

 Speed (km/h).............................................96.4 Maximum Roll Angle.............................. -24.3

 Angle (deg)............................................... 25 Maximum Pitch Angle.............................. -10.7 Impact Severity (kJ) ................................ 127.6 Maximum Yaw Angle.............................. 59.1

 Page 12 of 41

STI Project:

 QBD08

Barrier Systems, Inc.

RTS-QMB Safety Barrier