Pedestrian safety impacts of curb extensions : a case study : final report.

Johnson, Randal S. · 2005 · ROSA P / Oregon. Dept. of Transportation. Research Unit

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Summary

This study evaluates the impact of curb extensions, continental crosswalk markings, and advance stop bars on motorist yielding behavior and pedestrian safety. Conducted in Albany, Oregon, the research addresses a gap in literature regarding the safety performance of curb extensions, which are often studied primarily for traffic calming rather than pedestrian protection. The City of Albany installed these features in 2003 at intersections along U.S. Highway 20 to improve visibility and shorten crossing distances on high-volume, uncontrolled streets. The study specifically aimed to quantify whether these improvements functioned as intended by analyzing driver behavior. The research focused on the intersection of 4th Avenue and Lyon Street, which offered a unique treatment-and-control design. The nearside crosswalk featured a curb extension on the west side but retained the original curb line on the east side due to a nearby driveway. This configuration allowed for a direct comparison of motorist behavior toward pedestrians crossing from the treated side versus the untreated side, while controlling for variables such as traffic volume, markings, and driver population. Data were collected via video recording during daylight hours, utilizing both natural and staged pedestrians to ensure sufficient sample sizes. The study measured three key metrics: the average number of vehicles passing before a pedestrian crossed, the percentage of crossings where a motorist yielded, and the percentage of vehicles yielding at the advance stop bar. Statistical significance was assessed using two-sample t-tests. The results indicated that curb extensions significantly reduced the number of vehicles passing before a pedestrian could cross. In the near lane, the mean number of passing vehicles dropped from 2.58 to 1.81 (a 42.7% reduction), and in the far lane, it decreased from 2.36 to 1.76 (a 33.9% reduction). Both reductions were statistically significant (p < 0.05). However, the percentage of crossings where motorists yielded showed only slight, statistically insignificant increases (2.7% in the near lane and 7.7% in the far lane). Similarly, while the percentage of vehicles yielding at the advance stop bar increased by approximately 20% with the curb extension, this improvement was also statistically insignificant. Overall, only about 60% of crossings involved a yield, and only half of yielding drivers stopped at the advance stop bar, leaving a risk of "multi-threat" collisions where near-lane vehicles block the view of far-lane drivers. The study concludes that curb extensions effectively improve sight distance and reduce the number of vehicles passing pedestrians, thereby enhancing safety. However, the limited improvement in yielding behavior at advance stop bars suggests that these features alone may not fully mitigate multi-threat collision risks. The findings provide a methodology for evaluating curb extension performance and highlight the need for additional treatments or enforcement to improve driver compliance with yielding behaviors.

Key finding

Curb extensions significantly reduced the average number of vehicles passing before a pedestrian crossed, but did not produce statistically significant increases in motorist yielding rates or advance stop bar compliance.

Methodology

field_study

Sample size: 234

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

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• driver vru interaction
• pedestrian behavior perception