8.2.2 Define Evaluation Criteria

Selecting evaluation criteria demands engineering judgement and is typically coordinated with project stakeholders prior to proceeding with alternatives evaluation. Evaluation criteria are quantitative (MOEs) or qualitative indicators that enumerate impacts (good and bad) of an alternative. Traffic and Safety Analysis Procedures Manual | 2024 8-4 presents a flow diagram of potential evaluation criteria.
Evaluation Criteria
Figure 8-2: Evaluation Criteria
Criteria Definition Guidance:
  • Objectivity:
     It is suggested that evaluation criteria aim to be objective and without bias.
  • Criteria groups:
     Evaluation criteria that represent a range of project impacts and reflect all project goals/objectives selected. Common criteria groups include safety, mobility, access, environmental, and cost (see ).
  • Quantitative criteria:
     Quantitative criteria are preferred and can include the MOEs discussed in
    Chapter 4
    . Common quantitative criteria include crash rate, crash frequency, LOS, impacted residential parcels, and OD travel times.
  • Qualitative criteria:
     For high-level evaluations where MOEs may not be feasible, qualitative criteria can be precisely defined and criterion scoring can be annotated. Examples of qualitative criteria are conflict points and driver expectancy. Conflict points help identify potential safety issues. Driver expectancy is another qualitative criterion that relates to a driver's readiness to respond accurately and promptly to situations, events, and information while driving.
  • Quantitative comparison:
     Quantitative metrics can be reported for each alternative and then qualitatively “scored” to compare impacts between criteria.
  • Trade-offs:
     A wide range of criteria can be employed to highlight benefits and costs of each alternative. This certifies trade-offs, or specific costs associated with selected benefits, are evaluated as part of the decision-making process.
  • Weighting criteria:
     Trade-offs can be plainly demonstrated by weighting criteria; weights are assigned in proportion to the importance of each criterion. However, weighting criterion, as with assigning exact values to qualitative criterion, may misrepresent project impacts or over-complicate the alternatives analysis.
  • Redundant criteria:
     It is recommended that redundant criteria (such as intersection LOS and control delay) be valued appropriately to avoid double-counting impacts.
  • Multi-tier alternatives analysis:
     Evaluation criteria can differ between evaluation tiers (see ). For example, a Tier 0 (fatal-flaw) analysis can evaluate twelve Planning-level alternatives using sketch-level or macroscopic tools. A Tier 1 (preliminary) analysis can evaluate six Preliminary Schematics-level alternatives using HCM-based (mesoscopic) tools. A Tier 2 (detailed) analysis can evaluate three Advanced Schematics and Design-level alternatives using microsimulation (microscopic) tools.
Table 8-1: Multi-Tier Alternatives Analysis Objectives and Sample Criteria
Analysis Tier
Objective
Sample Criteria
Tier 0 (Fatal Flaw)
Develop viable alternatives that satisfy the project’s purpose and need. Often evaluated using sketch-level or macroscopic tools based on a high-level sketch of the alternative.
  • Includes multi-modal infrastructure
  • Within existing ROW
Tier 1 (Preliminary)
Refine viable alternatives for further evaluation. Often evaluated using a TDM output or HCM-based (mesoscopic) tools
  • Expected to reduce crash frequency (assessed qualitatively)
  • V/C ratio reduced within study area
Tier 2 (Detailed)
Select the alternative that best satisfies the project’s purpose and need. Often evaluated using microsimulation (microscopic) or HCM -based (mesoscopic) tools.
  • Net present value (NPV) of crash savings
  • Delay and travel time
  • Initial construction cost