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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Safety Eligibility Letter LS-67

Hardware Type:
Luminaire Supports
Code:
LS-67
Date:
Testing Criteria:
NCHRP 350
Manufacturer:
Dynamic Lighting Systems
Device Description:
Dynamic Lighting decorative poles and ground stub
View PDF:
ls67.pdf (2.38 MB)

"FHWA Logo"

 

1200 New Jersey Ave., S.E.
Washington, DC 20590

 

 

May 30, 2008

In Reply Refer to: HSSD/LS-67

Mr. Travis Rock
Dynamic Lighting Inc.
5220 Shank Rd
Houston, TX 77581

Dear Mr. Rock:

This letter is in response to your request for Federal Highway Administration (FHWA) acceptance of a roadside safety device for use on the National Highway System (NHS).

  • Name of device: Dynamic Lighting decorative poles and ground stub
  • Type of device: Luminaire Support
  • Test Level: Test Level 3 (TL-3)
  • Testing conducted by: Texas Transportation Institute (TTI)
  • Date of request: May 6, 2008
  • Date of follow-up: May 20, 2008

You requested that we find this device acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.”

Requirements
Roadside safety devices should meet the guidelines contained in the NCHRP Report 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". FHWA Memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 25, 1997 provides further guidance on crash testing requirements of luminaire supports.

Description
The following two Dynamic Lighting decorative luminaire installations were tested at the TTI outdoor pendulum testing facility:

  1. Dynamic Lighting pole base 26706B was connected to a fluted luminaire and attached to a Dynamic Lighting ground stub FDBE36 as shown in the enclosed drawings. The 36-inch (0.91 m) ground stub was installed in NCHRP 350 standard soil. The total height of the base and pole is 13 feet 10 inches (4.22 m). The base is cast aluminum (alloy A319) with an 11-1/2 inch (292.1 mm) square base bottom tapering to an octagonal shape for a base height of 25-1/4 inches (641.35 mm). Drawings of the Dynamic Lighting pole cast base assembly 26706B, pole, and ground stub FDBE36 are enclosed. The Dynamic Lighting pole base 26706B with luminaire pole was also tested while attached to a rigid steel reaction plate to simulate a fixed anchorage.

  2. Dynamic Lighting pole base 26706A was connected to a fluted luminaire and attached to a rigid steel reaction plate to simulate a fixed anchorage. The total height of the base and pole is 15 feet 6 inches (4.72 m). The base is cast aluminum (alloy A319) with a 17 inch (431.8 mm) diameter base bottom tapering to a 5 inch (127 mm) diameter and overall base height is 17-1/4 inches (438.15 mm). A drawing of the Dynamic Lighting pole cast base assembly 26706A and pole is enclosed.

Crash Testing
Your company’s decorative lighting poles were tested at TTI’s outdoor pendulum testing facility as a surrogate for full-scale crash testing. The pendulum bogie was built according the specifications of the Federal Outdoor Impact Laboratory's (FOIL) pendulum, and the frontal crush of the aluminum honeycomb nose of the bogie simulated the crush of an actual vehicle. Tests with pendulums are acceptable for most breakaway supports, exceptions being base bending or yielding supports.

Three low speed pendulum tests were conducted on your company’s decorative lighting supports, one test on each of the pole installations. Summaries of test results are enclosed. All Decorative Lighting Poles met the NCHRP Report 350 occupant risk criteria.

In tests with Dynamic Lighting pole base 26706B (surface mount and embedded ground stub FDBE36) and Dynamic Lighting pole base 26706A, the base separated from the ground and the lighting pole separated from the decorative base section. The base fractured at ground line and this performance satisfies the FHWA limit of maximum 3.9 inch (100 mm) stub height remaining after a support breaks away.

Findings
In summary, the Dynamic Lighting pole base 26706B (with the surface mount or the embedded ground stub FDBE36) and Dynamic Lighting pole base 26706A with decorative lighting poles, meet the appropriate evaluation criteria for a NCHRP 350 TL-3 device. They may be used at all appropriate locations on the NHS when selected by the contracting authority, subject to the provisions of Title 23, Code of Federal Regulations, Section 635.411 as they pertain to proprietary products. The Dynamic Lighting pole base 26706B (surface mount and embedded ground stub FDBE36) is accepted with luminaire pole mounting heights up to13 feet 10 inches (4.22 m), with shafts up to 0.188 inch (4.78 mm) wall thickness, and diameters up to 4 inches (101.6 mm). The ground stub FDBE36 must have a 0.188 inch (4.78 mm) wall thickness and embedment length of at least 36 inches (0.91m) in NCHRP standard soil. The Dynamic Lighting pole base 26706A is accepted with luminaire pole heights up to 15 feet 6 inches (4.72 m), with shafts up to 0.155 inch (3.94 mm) wall thickness, and with diameters up to 5 inches (127 mm).

Standard provisions
Please note the following standard provisions that apply to FHWA letters of acceptance:

  • This acceptance is limited to the crashworthiness characteristics of the device and does not cover their structural features, nor conformity with the Manual on Uniform Traffic Control Devices.
  • Any changes that may adversely influence the crashworthiness of the device/system will require a new acceptance letter.
  • Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals unacceptable safety problems, or that the device/system being marketed is significantly different from the version that was crash tested, we reserve the right to modify or revoke our acceptance.
  • You will be expected to supply potential users with sufficient information on design and installation requirements to ensure proper performance.
  • You will be expected to certify to potential users that the hardware furnished has essentially the same chemistry, mechanical properties, and geometry as that submitted for acceptance, and that it will meet the crashworthiness requirements of the FHWA and the NCHRP Report 350.
  • To prevent misunderstanding by others, this letter of acceptance is designated as number LS-67 and shall not be reproduced except in full. This letter and the test documentation upon which it is based are public information. All such letters and documentation may be reviewed at our office upon request.
  • The Dynamic Lighting decorative luminaire supports are patented products and considered proprietary. If proprietary devices/systems are specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS projects, they: (a) must be supplied through competitive bidding with equally suitable unpatented items; (b) the highway agency must certify that they are essential for synchronization with the existing highway facilities or that no equally suitable alternative exists; or (c) they must be used for research or for a distinctive type of construction on relatively short sections of road for experimental purposes. Our regulations concerning proprietary products are contained in Title 23, Code of Federal Regulations, Section 635.411.
  • This acceptance letter shall not be construed as authorization or consent by the FHWA to use, manufacture, or sell any patented device/system for which the applicant is not the patent holder. The acceptance letter is limited to the crashworthiness characteristics of the candidate device/system, and the FHWA is neither prepared nor required to become involved in issues concerning patent law. Patent issues, if any, are to be resolved by the applicant.
 

Sincerely yours,

"David A. Nicol signature"

David A. Nicol, P.E.
Director, Office of Safety Design
Office of Safety

Enclosures