In driving the back roads of Texas, it becomes quite apparent that there is little uniformity in the way bridge ends are marked. Quite often, there are no markings at all.
There may be many reasons why this lack of uniformity exists; one reason may be that while the Texas Manual on Uniform Traffic Control Devices (TMUTCD) addresses the various traffic control components that may be used to mark bridge ends, the TMUTCD does not contain a specific illustration or example for this situation.
TxDOT’s Traffic Engineering Standard Plan Sheets do, however, contain guidance information and illustrations for marking bridge ends. These guidelines and illustrations, though not binding on local road agencies, do provide good examples of “best management practices” that can be adopted for use by any local entity wishing to improve the safety of the bridges on their system.
These guidelines and illustrations are found on the TxDOT standard plan sheet labeled Delineator and Object Marker Placement Details D & OM (3)-04
By following these guidelines and improving the visibility of bridge approaches, especially in rural areas, it is possible to improve the overall bridge safety of any roadway system.
The following quotation (from Traffic Control Devices Handbook, Federal Highway Administration, 1983) may be helpful in explaining the meaning and purpose of the roadway delineation concept:
“The primary purpose of a roadway delineation system is to provide the visual information needed by the driver to steer a vehicle safely in a variety of situations. The delineation technique used must define the path of safe travel and must be visible in daylight and darkness and in periods of adverse weather such as rain and fog.”
To access TxDOT’s standard plan sheet D & OM (3)-04:
Go to http://www.dot.state.tx.us/
Click on “Business”
Scroll down. Under the heading “Specifications and Plans,” click on “CAD Standards”
At the bottom of the page, click “I Accept”
Scroll down. Under “Traffic Operations Division,” click on “Traffic Engineering Standard Plan Sheets (English and Metric)”
Scroll down. Under “Delineator and Pavement Marker Standards,” click on “Delineators and Object Markers” (PDF icon titled “dom04.dgn”
Scroll to D & OM (3)-04
By Bill Tucker, P. E., and Howard McCann, P. E. Bill Tucker, P.E., is a Texas Engineering Extension Service (TEEX) Adjunct Instructor. Howard McCann, P.E., is TEEX’s Transportation Engineering Program Manager. Thanks to Doug Skowronek, P. E., of TxDOT’s Traffic Operations Division for providing valuable technical information. This article reproduced with permission from TEEX’s March-April issue of Lone Star Roads. To view additional issues of Lone Star Roads, go to http://teexcit.tamu.edu/texasltap/newsletter.html.
By Bill Tucker, P. E., and Howard McCann, P. E.