USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        Safety
                        Roadway Departure Safety
                        Reduce Crash Severity
                        Hardware Eligibility Letters


            
            In This Section
        Roadway Departure Safety
                Strategic Approach
                                Strategic Plan
                Crash Emphasis Brochures
                Focused Approach
                Noteworthy Practices
                Partner Resources
                Keep Vehicles on the Road
                                Pavement Friction
                Horizontal Curve Safety
                Rumble Strips and Rumble Stripes
                Nighttime Visibility
                Provide for a Safe Recovery
                                SafetyEdge
                Clear Zones
                Reduce Crash Severity
                                Overview
                Hardware Eligibility Letters
                Focus on Reducing Rural Roadway Departures (FoRRRwD)
                                Overview
                All Public Roads
                Proven Countermeasures
                Systemic Approach
                Safety Action Plans
                FoRRRwD Resources
                
                Safety Eligibility Letter WZ-149
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-149
                          **Date:**
            03/21/2003
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            MWRSF
                          **Device Description:**
            Michigan Portable Sign Stand
                          **View PDF:**
            wz149.pdf (486.11 KB)
    
    



March 21, 2003
Refer to: HSA-10/WZ-149
Ronald K. Faller,
Ph.D., P.E.
Research Assistant
Professor
Midwest Roadside Safety
Facility
University of Nebraska,
Lincoln 
527 Nebraska Hall
P.O.
Box 880529
Lincoln, Nebraska  68588-0529
Dear Dr. Faller:
This is in response to your letter of February 5, 2003,
requesting Federal Highway Administration (FHWA) acceptance of the Michigan
Department of Transportation's Temporary Sign Stand as a crashworthy traffic
control device for use in work zones on the National Highway System (NHS).  Accompanying your letter were reports of
crash testing conducted by the Midwest Roadside Safety Facility and video of
the tests.  You requested that we find
these devices 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."
**Introduction**
The FHWA guidance on crash testing of work zone traffic
control devices is contained in two memoranda. The first, dated July 25, 1997, titled "INFORMATION: Identifying
Acceptable Highway Safety Features," established four categories of work zone
devices: Category I devices were those lightweight devices which could be
self-certified by the vendor, Category II devices were other lightweight
devices which needed individual crash testing, Category III devices were
barriers and other fixed or massive devices also needing crash testing, and
Category IV devices were trailer mounted lighted signs, arrow panels, etc. The second guidance memorandum was issued on
August 28, 1998, and is titled "INFORMATION: Crash Tested Work Zone
Traffic Control Devices." This later
memorandum lists devices that are acceptable under Categories I, II, and III.
A brief description of the sign stand follows:
(System Nos. 5 and 6) a 1,730-mm wide x 1,829-mm
deep x 3,264-mm tall steel sign support with a 1,219-mm x 1,219-mm x 15.9-mm
thick plywood diamond-shaped sign panel with reflective material mounted at a
height of 1,540 mm from the ground to the bottom of the sign panel and with a
lightweight "Empco-Lite" Type A warning light mounted at a height of 2,597 mm
from the ground to the top of the warning light and with 15.88 kg of sandbags
at the end of each leg.
**Testing**
A total of six devices were crash tested as part of the
Michigan DOT program.  System Nos. 1 and
2 were the original version of the stand which failed due to passenger
compartment intrusion. System Nos. 3 and 4 were 12-foot long Type III
barricades which also failed to meet the evaluation criteria.  System Nos. 5 and 6 were the redesigned sign
stand using stiffened masts, relocated warning light, revised sign-to-post
fasteners, and the omission of the speed advisory plate.
Full-scale automobile testing was conducted on the final
design of the sign stand.  Two
stand-alone examples were tested in tandem, one oriented at 90 degrees to
travel, and the next placed 60 feet downstream at a head-on orientation, as
called for in our guidance memoranda. 
The successfully tested stand was modified from an earlier design that
was tested in a prior crash test program.
The tests are summarized in the table below.
Michigan Temporary
  Sign StandTest Number
MI-3, System 5
MI-3, System 6Sign Stand Orientation
90 degrees  (End-on)
0 degree  (Head-on)Weight of Stand, Sign, Light
53.5 kg +/-
53.5 kg +/-Mounting heights
1540 mm
1540 mmFlags? Lights?
Empco Lite Model
  400
Empco Lite Model
  400Mass of Sand Ballast
One 31.75 kg bag at each end of each legMass of Test Vehicle
896 kgImpact Speed
101.0 km/hr
91.3 km/hr *Velocity Change
2.7 m/s
n/aExtent of contact
95 mm roof crushWindshield Damage
Spider cracking in
  upper right. No deformation or holeOther notes
*Low speed is
  acceptable.**Findings**
Damage was limited to the front end of the vehicle (bumper,
grill, radiator), minor spider cracking of a portion of the windshield, and 95
mm of roof deformation (from the corner of the 90-degree orientation sign
panel, in the vicinity of the warning light.) 
The velocity change caused by System 5 (90-degree orientation) slowed
the vehicle enough to drop it below the tolerance for a 100 km/hr test.  The possibility of this occurring was known
when FHWA established the recommendation to hit two examples of the device on
the same run of the test vehicle.  We
concur in your analysis that the damage would not have been significantly
greater had System 6 been struck at 100 km/hr. 
The results of the testing met the FHWA requirements and, therefore, the
Michigan Temporary Sign Stand described above and detailed in the enclosed
drawings are acceptable for use on the NHS under the range of conditions
tested, when proposed by a State.
Please note the following standard provisions that apply to
FHWA letters of acceptance:
Our acceptance is
limited to the crashworthiness characteristics of the devices and does not
cover their structural features, or conformity with the Manual on Uniform
Traffic Control Devices.
Any changes that may
adversely influence the crashworthiness of the device 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 being marketed is
significantly different from the version that was crash tested, it reserves the
right to modify or revoke its acceptance.
You or the Michigan DOT
will be expected to supply potential users with sufficient information on
design and installation requirements to ensure proper performance.
You or the Michigan DOT
should supply information to potential users that would allow them to certify
that the hardware furnished has essentially the same chemistry, mechanical
properties, and geometry as that submitted for acceptance, and that they will
meet the 
crashworthiness requirements of FHWA and NCHRP Report 350.
To prevent
misunderstanding by others, this letter of acceptance, designated by the FHWA
as number WZ-149 shall not be reproduced except in full.  This letter, and the test documentation upon
which this letter is based, is public information.  All such letters and documentation may be reviewed at our office
upon request.Sincerely yours,
Michael S.
Griffith
Acting
Director, Office of Safety Design
Office of Safety
Enclosures U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us