WIS 75 Intersection Screening & Project Development Process

Hamilton, Ian · 2021 · ROSA P / United States. Department of Transportation. Federal Highway Administration. Office of Safety

archive: archived pipeline: cataloged verified

Get this paper ↗ (full text — opens at the source; we link to it, we don't host it)

Summary

This case study documents the Wisconsin Department of Transportation’s (WisDOT) application of the Highway Safety Manual (HSM) to evaluate and improve safety at the intersection of State Highway 75 (WIS 75) and County Road A in Racine County. The project was motivated by the need to integrate data-driven safety analysis into routine infrastructure planning, specifically leveraging a scheduled 2023 resurfacing project to implement Highway Safety Improvement Program (HSIP) countermeasures. The study aims to demonstrate how state agencies can use institutionalized screening and diagnostic processes to identify safety needs and select cost-effective treatments. WisDOT employed a multi-step analytical framework beginning with network screening using State-specific tools, including the MetaManager and an Intersection Network Screening Spreadsheet. The intersection received a Level of Service of Safety (LOSS) rating of IV, indicating a high potential for crash reduction, with an observed crash rate of 3.7 crashes per million entering vehicles between 2014 and 2019. A diagnostic review of crash history revealed that the primary safety issue was failure-to-yield crashes, where vehicles on the stop-controlled County Road A approaches collided with through traffic on WIS 75. To evaluate potential solutions, WisDOT used the Interactive Highway Safety Design Model (IHSDM) to predict crashes for three alternatives: the existing two-way stop control, an all-way stop control, and a four-leg roundabout. Due to limited recent traffic data, the analysis relied on 1999 turning movement counts adjusted for growth, alongside State-calibrated safety performance functions (SPFs) and crash modification factors (CMFs). The results indicated that the all-way stop control alternative predicted the fewest total crashes, while the roundabout predicted the fewest fatal and serious injury crashes. However, the economic appraisal determined that the all-way stop control was the most cost-effective option, yielding a benefit/cost ratio (BCR) of 13.67. In contrast, the roundalternative had a BCR of 0.76, as the high costs of right-of-way acquisition and construction outweighed the predicted safety benefits. Consequently, WisDOT recommended implementing an all-way stop as an interim solution, while noting that a roundabout should be considered for future permanent improvements due to concerns regarding driver compliance with stop signs. The significance of this study lies in its demonstration of a repeatable, institutional process for integrating safety analysis into project development. By combining network screening, diagnostic diagnosis, and economic appraisal, WisDOT successfully identified a targeted safety intervention that aligns with routine maintenance schedules. The case highlights the practical utility of HSM methods, such as LOSS ratings and IHSDM modeling, in making evidence-based decisions. It also underscores challenges in applying standardized models to specific local conditions, emphasizing the importance of the diagnostic phase in interpreting crash data and selecting appropriate countermeasures.

Key finding

The all-way stop control alternative was identified as the most cost-effective safety treatment with a benefit-cost ratio of 13.67, significantly outperforming the roundabout option which had a ratio of 0.76.

Methodology

modeling

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed. Discovered via bulk_ingest_rosap on 2026-05-23 (6 acquisition events logged).

Summary generated by qwen3.6-27b-prismaquant on 2026-06-10; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• roadway lighting effects
• regulatory evaluation
• intersection design

Information type

What kind of knowledge this paper contributes, grouped by family — independent of topic (what it is about) and method (how it was studied).

• Applied Guidance: countermeasure evaluation
• Empirical Findings: crash risk outcomes