Understanding the Importance of Weight Limit Signs: Keeping Your Bridges Strong & Healthy No. 3

Bridges are typically posted with a weight restriction because a structural member(s) within the bridge has succumb to deterioration resulting in a reduction of that members structural capacity to carry the pre-design loads.  In most instances, bridges are weight restricted for the deterioration of a bridge beam.  Once a bridge is recommended for a weight restriction by a registered Professional Engineer, it is the responsibility of the bridge owner to adequately and properly place the weight limit signs at the structure and the nearest advance intersection based on the recommendation and maintain the signs as long as the structure is weight restricted.  It is important that bridge owners follow the correct load posting procedures for each of their weight restricted bridges to:

1.       Legally protect the structure from overweight vehicles.

2.       Allows law enforcement to prosecute (fine) overweight vehicles users.

3.       Protects the bridge owner in the event of a catastrophic failure from an  overweight vehicle.  A catastrophic failure could result in personal injury and expensive repairs.  If signs are not placed in accordance with the PA Vehicle Code, the bridge owner could be liable.

When a municipality receives a weight restriction notification or signing deficiency letter from a bridge inspection, it is a PennDOT mandatory requirement that all signing deficiencies be repaired within 7 days of the inspection date.

Some things to remember about load posting assemblies and placement:

  • All load posting assemblies are to be within 25’ of the bridge and nearest intersection.
  • Keep all signs visible to motorist and in the correct order on the post.
  • It is recommended no other signs are  to be placed on the post with the weight limit signs.
  • Keep the bottom of the bottom sign approximately 5 feet above the finished roadway surface.

For More Information

Follow the link to PA Vehicle Code for further information on erection of signs and additional information on maximum weights of vehicles, etc.