Overweight Permit Loads are classified as Routine or Superheavy. Routine Overweight Permit Loads may be allowed in the regular traffic stream. An escort is required if the load is also over-length or overwidth. Use the standard AASHTO load distributions since there may be a legal truck alongside the Routine Overweight Permit Load truck crossing a bridge at the same time.

The term Superheavy Permit Load designates total loads over 254,300 lbs. gross. It consists of a 14,300 lb steering axle followed by four groups of three axles, each totaling 60,000 lbs. Any configuration with multiple axles with a gross load of over 254,300 lbs. is considered a Superheavy load and requires structural evaluation of individual bridges. Loads with individual axles or axle group weights that exceed the maximum permit weights are also considered to be Superheavy. Any load exceeding 200,000 lbs. with a total overall length of less than 95 feet is also considered Superheavy.

More information on superheavy permit requirements and procedures is given on the Texas Department of Motor Vehicles – Motor Carriers website at http://www.txdmv.gov/motorcarriers.

The Superheavy Permit may require a specific configuration such that the load straddles multiple lanes. This loading may be such that other legal trucks will not be alongside the Superheavy load and gives better load distribution. In such situations, the AASHTO load distributions used for Superheavy loads are, therefore, usually single lane.

A printout of the proposed list of bridges to be crossed is reviewed by the TxDMV and the Bridge Division. It may be necessary to structurally evaluate only a portion of the bridges on an extensive proposed Superheavy route. For any bridges on the route with a Deck, Superstructure or Substructure condition Rating of 4 or less, review the actual written Bridge Inspection Record. This bridge-by-bridge evaluation is one of the primary reasons that the data in the Bridge Inspection Management System must be accurate and up-to-date.