Texas Department of Transportation
DEWITT C. GREER STATE HIGHWAY BLDG.
125 E. 11TH STREET
AUSTIN, TEXAS 78701-2483
(512) 463-8585
March 12, 2003
Mr. Ernest Huckaby
Federal Highway Administration
Office of Transportation Operations
Room 3408
400 Seventh Street., S.W.
Washington, D.C. 20590
Dear Mr. Huckaby:
The Texas Department of Transportation would like to request permission from the Federal Highway Administration to experiment with a non-standard sign application as part of the evaluations for TxDOT/TTI research project 0-4413, Advanced Warning of Stopped Traffic.
Purpose:
A major safety concern in freeway operations is traffic flowing at normal speed encountering unexpected stopped traffic on the freeway main lanes. Traffic can be queued due to recurrent congestion during peak periods, construction or maintenance in work zones, crashes or other incidents. Drivers encountering queues are often faced with rapidly changing conditions in terms of queue length, sight distance to the end of queue, terrain, and available warning devices for traffic control. The most common type of multi-vehicle freeway crash is a rear-end collision, often due to stopped traffic on the freeway main lanes.
TxDOT has placed a high priority on informing drivers of roadway conditions in real-time, in terms of construction and maintenance signing for work zones and via Intelligent Transportation System strategies for incident conditions. However, techniques and strategies for providing drivers with real-time advanced warning for stopped freeway conditions are not widely practiced on a routine basis.
The focus of this research will be to identify current practices and develop innovative techniques to provide advance warning of stopped traffic on freeways, thereby increasing safety and mobility.
Description of Traffic Control Device:
The non-standard sign and implementation arrangement for which we are requesting experimentation is a 48 X 48 inch yellow warning with a modified European queue symbol. A supplemental sign attached below to give more detail information concerning distance, etc. Please see the attachment for sign design and placement information.
Field Evaluation:
It is requested that permission be granted to experiment with the non- standard sign at a maximum of five locations on TxDOT highways. The field evaluations will include the daytime and nighttime effect of this non-standard sign on driver speeds and deceleration characteristics TxDOT and TTI staffs see no reason to believe that the R2-1 colored border extension will have adverse effects on traffic operations or safety while in place. However, the experiment will be terminated if it is determined that significant safety concerns are directly or indirectly attributable to the colored border used in this experiment.
Thank you for your consideration. If you have any questions or need additional information, please call me at (512) 416-3120.
Sincerely,
/s/
Greg Brinkmeyer, P.E.
Engineer of Policy and Standards
Traffic Operations Division-TE
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[Image shows a diamond-shaped sign indicating congestion. It is labeled "WATCH FOR CONGESTION NEXT X MILES." (See pdf version to view images.)]
NEXT X MILES is text for first set of signs only.
[Image shows a diagram of the location of a detection zone ahead of the location of the warning signs. (See pdf version to view images.)]
Text on plaque:
WHEN FLASHING
If no detection zone is used, and flashers are always on, then text on plaque may be:
WATCH FOR STOPPED TRAFFIC
[Image shows a diamond-shaped sign that reads "WATCHED FOR STOPPED TRAFFIC AHEAD." (See pdf version to view images.)]
"AHEAD" is text for the first set of signs only.
[Image shows a diagram of the location of a detection zone ahead of the location of the warning signs. (See pdf version to view images.)]
Text on plaque:
WHEN FLASHING
GENERAL PURPOSE TRAILER MOUNTED CHANGEABLE MESSAGE SIGN
with alphanumeric and graphic display capability
[Image shows a photo of the display. (See pdf version to view images.)]