March 11, 1999 Refer to: HMHS-B50

Mr. James M. Sime

Assistant Manager for Research

Connecticut Department of Transportation

280 West Street

Rocky Hill, CT 06067

Dear Mr. Sime:

In your January 25, 1999, letter to the Director of the Federal Highway Administration’s Office of

Engineering, you requested acceptance of two bridge rail designs that were developed and tested

for use on the National Highway System (NHS) by the New England Transportation Consortium

(NETC).

The first design is the NETC 2-Bar Curb-Mounted Bridge Railing shown as Enclosure 1. This

design was tested to Performance Level 2 (PL-2) in accordance with the AASHTO Guide

Specifications for Bridge Railings and was effectively accepted as an NCHRP Report 350 Test

Level 4 (TL-4) railing by its inclusion in the summary listings attached to my May 30, 1997

memorandum on crash testing of bridge railings.

The second design is the NETC 4-Bar Sidewalk-Mounted Bridge Railing shown as Enclosure 2,

and documented in four publications, FHWA-RD-99-027, FHWA-RD-99-028, FHWA-RD-99-

029, and FHWA-RD-99-030, each entitled “Full-Scale Crash Evaluation of Sidewalk-Mounted

Steel Bridge Railing”. Review of each crash test report showed that the 4-Bar Bridge Railing met

all appropriate evaluation criteria for an NCHRP Report 350 traffic barrier at TL-4. Summary

sheets on each of the three tests that were conducted are attached as Enclosure 3.

Based on the information you provided for our review, we conclude that both the NETC 2-Bar

Curb-Mounted Bridge Rail and the 4-Bar Sidewalk-Mounted Bridge Rail are acceptable as TL-4

designs and may be used on the NHS when selected by a transportation agency. We understand

that neither design is proprietary and that anyone wishing to obtain detailed plans and

specifications may contact you by telephone at (860) 258-0309 or via e-mail at

james.simes@po.state.ct.us. We further understand that the NETC is currently developing

transitions to be tested in the near future for use with these two bridge railings.

Sincerely yours,

(original signed by Dwight A. Horne)

Dwight A. Horne

Director, Office of Highway Safety Infrastructure

3 Enclosures


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Figure 8. Impact sequence and summary of test conditions and results - Test NETC-1

* No occupant risk data - lateral accelerometer malfunctioned during test

4. General Information 7. Test Vehicle 

(Continued) 10. Ridedown Acceleration (g's)

Test Agency Southwest Research 

Institute Mass (kg) Dummy(s) 75 y-direction -

Test Number NETC-1 Mass (kg) Gross Static 902 11. Test Article Deflection (m)

Test Date 11/18/97 8. Impact Conditions Dynamic 0

5. Test Article Speed (km/h) 100.0 Permanent 0

Type Bridge Rail Angle (deg) 20.0 12. Vehicle Damage

Installation Length (m) 32.9 9. Exit Conditions Exterior

Barrier 4 Steel Rails Speed (km/h) 18.3 VDS 11-FL-2

6. Soil Type and 

Condition N/A Angle (deg) 6.6 CDC 11FLEE2

7. Test Vehicle 10. Occupant Risk 

Values Interior

Type Production Impact Velocity (m/s) OCDI LF0000000

Designation 820C x-direction -

13. Post-Impact Vehicular 

Behavior

Model 1991 Ford Festiva y-direction - Maximum Roll Angle (deg) 10 

Approximate

Mass (kg) Curb 827 Ridedown (g's) Maximum Pitch Angle (deg) 5 Approximate

Mass (kg) Test Inertial 827 X-direction - Maximum Yaw Angle (deg) 34 

Approximate
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Figure 11. Impact sequence and summary of test conditions and results - Test NETC-2.

4. General Information 7. Test Vehicle 

(Continued) 10. Ridedown Acceleration (g's)

Test Agency Southwest Research 

Institute Mass (kg) Dummy(s) N/A y-direction 14.30

Test Number NETC-3 Mass (kg) Gross Static 8,108 11. Test Article Deflection (m)

Test Date 12/18/97 8. Impact Conditions Dynamic 25

5. Test Article Speed (km/h) 80.0 Permanent 13

Type Bridge Rail Angle (deg) 15.0 12. Vehicle Damage

Installation LEngth (m) 34.1 9. Exit Conditions Exterior

Barrier 4 Rails, Sidewalk-Mounted Speed (km/h) 57,6 VDS N/A

6. Soil Type and 

Condition N/A Angle (deg) 4.1 CDC N/A

7. Test Vehicle 10. Occupant Risk 

Values Interior

Type Production Impact Velocity (m/s) OCDI N/A

Designation 8000S x-direction 1.65 13. Post-Impact Vehicular 

Behavior

Model 1993 International 4600 LP y-direction -2.89 Maximum Roll Angle (deg) 20 

Approximate

Mass (kg) Curb 8,108 Ridedown (g's) Maximum Pitch Angle (deg) 5 Approximate

Mass (kg) Test Inertial 8,108 X-direction -8.95 Maximum Yaw Angle (deg) N/A
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Figure 11. Impact sequence and summary of test conditions and results - Test NETC-3 

4. General Information 7. Test Vehicle 

(Continued) 10. Ridedown Acceleration (g's)

Test Agency Southwest Research 

Institute Mass (kg) Dummy(s) 75 y-direction -

Test Number NETC-2 Mass (kg) Gross Static 2,109 11. Test Article Deflection (m)

Test Date 11/20/97 8. Impact Conditions Dynamic 25 (est.)

5. Test Article Speed (km/h) 100.0 Permanent 13

Type Bridge Rail Angle (deg) 25.0 12. Vehicle Damage

Installation LEngth (m) 34.1 9. Exit Conditions Exterior

Barrier 4 Bar, Sidewalk Mounted Speed (km/h) 17 VDS 11-FL-3

6. Soil Type and 

Condition N/A Angle (deg) 8.2 CDC 11FLEE3

7. Test Vehicle 10. Occupant Risk 

Values Interior

Type Production Impact Velocity (m/s) OCDI LF0000000

Designation 2000P x-direction 3,99 13. Post-Impact Vehicular 

Behavior

Model 1991 Ford F-250 y-direction - Maximum Roll Angle (deg) 20 

Approximate

Mass (kg) Curb 2,034 Ridedown (g's) Maximum Pitch Angle (deg) 15 

Approximate

Mass (kg) Test Inertial 2,034 X-direction -2.55 Maximum Yaw Angle (deg) N/A