Warning signs are intended to improve curve safety by alerting the driver to a change in geometry that may not be apparent or expected. These signs notify drivers of the change through the use of one or more curve warning signs identified in the

Texas Manual on Uniform Traffic Control Devices

( ). Drivers may also be notified of the need to reduce their speed through the use of a W13-1 ADVISORY SPEED plaque.

When one or more warning signs are used at a horizontal curve, the curve advisory speed and other curve related traffic control devices should be checked periodically to ensure that they are appropriate for the prevailing conditions. Changes in the regulatory speed limit, curve geometry, or crash history may justify the conduct of an engineering study to reevaluate the appropriateness of the existing signs and posted advisory speed.