Evaluating Method 2 Horizontal Curvature in Freeway Work Zones: Safety, Suitability, and Alternatives
In freeway design, Method 5 is the standard approach for determining horizontal curvature on high-speed highways, while Method 2 is intended for low-speed urban facilities where higher side friction values are acceptable. However, in Utah, Method 2 has been implemented in high-speed freeway work zones through Alternative Technical Concepts (ATCs), most notably on the I-15 Technology Corridor project. Post-construction crash records revealed truck overturning incidents and other safety concerns, raising questions about the suitability of Method 2 in high-speed environments. While Utah Department of Transportation (UDOT) has already developed a five-year statewide database of work zones containing crash data (AASHTOWare Safety) and project details (Masterworks), this database does not distinguish between projects that used Method 2 horizontal curvature versus standard lane-shift tapers (Method 5). Without this distinction, UDOT lacks the ability to directly assess whether Method 2 increases crash severity, particularly for heavy vehicles, in comparison to established design practices. This gap in knowledge is critical given the safety implications for drivers and workers in high-speed freeway work zones, as well as the need to guide ATC approvals on future Design-Build projects. This research is needed to provide UDOT with a data-driven evaluation of Method 2’s risks, safety impacts, and design suitability in freeway work zones. Findings will clarify whether Method 2 should remain an acceptable option and under what conditions it might be safely applied.
Language
- English
Project
- Status: Active
- Funding: $60,000.00
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Contract Numbers:
268045
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Sponsor Organizations:
Utah Department of Transportation
Research and Innovation Division
Salt Lake City, UT United States 84114 -
Managing Organizations:
Utah Department of Transportation
Research and Innovation Division
Salt Lake City, UT United States 84114 -
Project Managers:
Jensen, Travis
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Performing Organizations:
Department of Civil and Environmental Engineering
110 Central Campus Drive Suite 2000
Salt Lake City, UT United States 84112 -
Principal Investigators:
Markovic, Nikola
- Start Date: 20251009
- Expected Completion Date: 20260831
- Actual Completion Date: 0
Subject/Index Terms
- TRT Terms: Crash rates; Freeways; Heavy vehicles; Highway curves; Highway design; Risk assessment; Work zone safety; Work zones
- Geographic Terms: Utah
- Subject Areas: Design; Highways; Safety and Human Factors;
Filing Info
- Accession Number: 01968453
- Record Type: Research project
- Source Agency: Utah Department of Transportation
- Contract Numbers: 268045
- Files: RIP, STATEDOT
- Created Date: Oct 13 2025 7:12PM