Phase II : operational and safety-based analyses of varied toll lane configurations.

Valdes, Didier; Colucci, B. · 2016 · ROSA P / Safety Research Using Simulation (SAFER-SIM) University Transportation Center

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 study evaluates the operational safety and driver behavior within the Puerto Rico Dynamic Toll Lane (DTL), a reversible managed lane system on freeway PR-22 that combines congestion pricing with shared use by private vehicles and Bus Rapid Transit (BRT). The research was motivated by observed safety concerns, including drivers exceeding posted speed limits, confusion at diverging segments, and frequent misuse of the BRT exit lane. The primary objective was to determine how lane width, posted speed limits, and time of day influence driving performance in this unique facility. The researchers employed a driving simulator at the University of Puerto Rico at Mayagüez to conduct a controlled experiment using a full factorial $3^3$ design. This design tested three independent variables, each at three levels: lane width (10, 11, and 12 feet), posted speed limit (45, 55, and 65 mph), and time of day (morning, evening, and night). A total of 27 scenarios were simulated by subject drivers. Driver performance was assessed using three surrogate safety measures: average speed, acceleration noise, and the standard deviation of roadway position (SDRP). These metrics were analyzed across five specific zones of interest along the DTL corridor, including areas near bridge piers and exits. The analysis of variance revealed that lane width significantly impacted average speed across all zones, with narrower lanes resulting in reduced speeds. Time of day negatively affected acceleration noise, with increased variability observed in Zones 2 through 5 during certain periods, suggesting a higher potential for crash frequency. Significant differences in SDRP were found between morning and night, as well as morning and evening conditions, particularly before and after the bridge pier separation. Additionally, approximately 26% of simulated scenarios involved drivers using the incorrect DTL exit (the BRT lane), with 57% of these errors occurring during morning scenarios. The study concludes that the optimal configuration for average speed in the PR-22 DTL is a posted speed limit of 55 mph combined with an 11-foot lane width. This research provides the first freeway safety evaluation of a managed lane system integrating reversible operations, congestion pricing, and BRT sharing. The findings highlight specific operational risks, such as exit confusion and speed variability, indicating a need for further research to develop countermeasures that enhance safety and efficiency in such complex managed lane facilities.

Key finding

Narrower lanes significantly reduced average speed, nighttime conditions increased acceleration noise, and drivers incorrectly used the Bus Rapid Transit exit in approximately 26% of simulated scenarios.

Methodology

simulator

Sample size: 27

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.

• work zones
• perceptual countermeasures
• traffic density
• speed choice
• lane changing
• speed management

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).

• Empirical Findings: behavioral performance data, observational prevalence
• Methodological Resource: dataset resource