If a project has a complete bridge replacement or a bridge-class culvert replacement, it is not eligible under 3R permissible scope of work. The 3R criteria will cover certain bridge upgrades, but "no bridge replacement". If a complete bridge replacement is included in a project, then the bridge must follow 4R Design Criteria even though the remainder of the project (such as approaching roadways) falls under 3R criteria. Consult with the Bridge Division as needed for additional information.

Where minimum bridge widths exist, it is generally expected that no additional structural work will be necessary. However, existing conditions such as deficient railing, deteriorated deck, or a structure with an deficient load carrying capability may require additional structural work. In such cases, refer to TxDOT’s and consult with BRG for design recommendations. If structural modification is necessary, it may be appropriate to consider a greater bridge width if future plans or traffic projections indicate additional roadway improvement will be necessary in the foreseeable future.

To accomplish a complete and cost-effective rehabilitation plan throughout a geographic area, identify roadways with low traffic volumes and perform a crash evaluation on structures with railings that do not match current standard railing details (reference TxDOT’s and TxDOT ). Evaluate bridges with these railings on an individual basis. If the evaluation indicates continuing satisfactory performance and the railing is in good repair, retain these railings on low volume roadways.

Obtain additional information on bridge rehabilitation refer to TxDOT’s .

Note that additional vertical clearance requirements may apply to bridge projects on the Texas Highway Freight Network (THFN), see .

A 5-ft minimum clear space for bicyclists should be provided on bridges being replaced or rehabilitated (An SUP may be used in lieu of the bicycle clear space). Off-system Bridges, with current ADT greater than 400 ADT, where this addition may represent an unreasonable increase in cost may be excepted from the bicycle clear space requirement. See for specific off-system bridge requirements for current ADT of 400 or less.