A PBPD approach should be utilized in all projects commensurate with the scope of the project. For 4R projects, the PBPD process can be used to optimize the design elements of a project that will provide the most safety at a better cost. The respective benefit-cost evaluation may use the tools and methods as described in the , or other available approved tools. The level of analysis should be commensurate with the size and scope of the project. These tools will use a present-day cost and value of benefits to develop a Benefit/Cost ratio (including safety benefits). Generally, B/C ratios of 2.0 or higher represent a significant benefit, while ratios between 2.0 and 1.0, though considered positive, require additional sensitivity analyses to determine whether the identified upgrades are sufficiently beneficial for the project and TxDOT. B/C values below 1.0 should generally not be considered. For those elements that it is determined from a Benefit-Costs standpoint that the design minimums for a particular element will not be achieved. The PBPD analysis would serve as the basis for any needed design exceptions or design waivers.

Design guidelines for 3R projects have been developed to allow for greater design flexibility. 3R design decisions should be based on an assessment of the safety and traffic operational performance of the existing road and the cost-effectiveness of potential design improvements. covers the application of PBPD for 3R projects and uses as the primary basis , and which has spreadsheet tools for comparing several alternatives or combinations of alternatives. There are additional tools and methodologies as referenced in the . As with 4R projects, the Benefit-Costs analyses would serve as the basis for any needed design exceptions or design waivers.

also covers roadway tradeoff cross-section optimization guidance for 4 lane and 2 lane roadways (a form of PBPD) that may be applicable to certain 4R projects as well.

The TxDOT Safer by Design Tools (found on the on TxDOT.gov), required for all applicable construction projects, is an additional tool available which utilizes proven safety measures based on the predictive method included in the . This tool is unique to Texas roadway facilities and provides quantitative scores specific to how a change in a roadway design may directly influence the safety performance of a roadway.