10.3.1 ICE Process Overview and Reporting

The two-stage ICE study procedure is beneficial for intersection analysis of intersection modification, reconstruction or where new construction is planned.
In Stage 1 the intersection analysis is a streamlined combination of operations and safety components:
  • Operational analysis using CAP-X and TMUTCD warrants; and
  • Safety analysis using SPICE
See
Appendix K, Section 3 – Intersection Analysis Checklist
 for an intersection analysis checklist. An expanded checklist is also provided for non-ICE type studies and system optimization considerations.
The main tools used in intersection analysis at Stage 1 are TMUTCD warrants (two-way stop controlled, AWSC, and signalized intersection), SPICE and CAP-X are considered sketch-level or macroscopic tools. Sketch-level or macroscopic analysis tools are typically used in analyzing individual intersections and large projects with interchanges or corridors, without requiring extensive resources. CAP-X is a pass-fail tool and not a ranking tool. The CAP-X LOS results are not granular enough to rank alternatives. Conversely, SPICE, in Stage 1, can be used as a ranking tool for all intersection control alternatives.
Stage 1 ICE considers all intersection control alternatives, ranks and removes the alternatives that do not meet the project’s purpose and needs based on existing conditions, field observations, and analyzed data. Conceptual exhibits of some intersection designs, such as roundabouts, help to determine the footprint and space needed. See
Chapter 8
 for additional information on alternatives analysis. Engineering judgement and a series of questions are considered during this determination. Does the alternative:
  • Meet the specified project goals and needs in a practical way?
  • Meet the applicable warrants?
    • See warrants for TWSC, AWSC, and signalized intersections below.
  • Address known crash history or improve future safety?
  • Demand additional ROW, and if so, how feasible will it be to acquire it?
  • Demand railroad coordination for ROW or encroachment?
  • Meet the TxDOT standards for turn-bay length?
  • Provide adequate left-turn capacity?
  • Have any known environmental impacts or produce higher emissions?
  • Provide a sustainable solution that is context-sensitive to any long-range plans and improvements?
  • Address stakeholder and public areas of interest?
  • Foster error-free driving tasks?
Stage 2 ICE applies more rigorous analysis of geometry, safety and operations, along with Traffic and Safety Analysis Procedures Manual | 2024 10-16 other factors such as cost and impacts (utilities, ROW, environmental, etc.). The main tools used in Stage 2 operations analysis are Synchro, HCS, and Vissim. The analysis software tool selection is based on intersection type, project complexity, and object level of detail (see ) for recommended analysis tools. The analysis tools recommended are example tools and other comparable software can be used. HCM-based (mesoscopic) tools are typically used when a more detailed analysis is necessary, but microsimulation (microscopic) analysis would be too much detail. Information related to the capabilities of the software is found in
Chapter 4 and Chapter 12, Appendix M
.
Appendix K, Section 1
 provides an abbreviated version of an ICE report. It covers the Stage 1 requirements and generates a preferred type of intersection control without requiring more detail that Stage 2 typically generates.
When both the safety (SPICE) and operations (CAP-X) analyses generate a clear preference for intersection control during the Stage 1 study tasks, Stage 2 ICE investigation may not be necessary, and the project can proceed to schematic design and detailed cost estimation. ICE Stage 2 is necessary when a clear preference for safety improvement is not evident in Stage 1, or where more detailed operational or impacts analysis is needed, such as where intersections are closely spaced.