Effects of full-facility variable tolling on traveler behavior : evidence from a panel study of the SR-520 corridor in Seattle.

Peirce, Sean; Puckett, Sean; Petrella, Margaret; Minnice, Paul; Ray, Rosalie; Lappin, Jane · 2014 · ROSA P / John A. Volpe National Transportation Systems Center (U.S.)

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 impact of full-facility variable tolling on traveler behavior in the Seattle region, specifically focusing on the SR-520 corridor across Lake Washington. Motivated by the U.S. Department of Transportation’s Urban Partnership Agreement and Congestion Reduction Demonstration programs, the research aims to understand how congestion pricing influences daily travel choices, mode selection, and traveler satisfaction. The SR-520 bridge, previously toll-free, implemented variable pricing in December 2011, with peak rates reaching $3.50 per trip, while the parallel I-90 bridge remained toll-free. The researchers employed a two-stage panel survey design involving approximately 2,000 households and over 3,600 adult respondents. Data collection occurred in two waves: Wave 1 (pre-tolling) in autumn 2010 and Wave 2 (post-tolling) in spring 2012. Participants completed two-day travel diaries recording trip details, alongside surveys on demographics, attitudes, and general travel patterns. The sample was stratified by mode and route, with data weighted to reflect actual peak-period travel volumes. The study also accounted for external factors, such as a 35% increase in gasoline prices between survey waves, which could independently influence travel demand. Key findings indicate a significant reduction in travel within the corridor following the implementation of tolling. Overall recorded trips in the Lake Washington corridor dropped by 18%, driven primarily by a 43% decrease in trips on SR-520 and a 52% reduction in vehicle-miles traveled (VMT) on that route. Conversely, I-90 saw a slight 3% increase in VMT, indicating substantial diversion to the toll-free alternative. Approximately one-fourth of former SR-520 drivers switched to I-90, a shift most pronounced among males, lower-income households, and those with less workplace schedule flexibility. While transit mode share increased modestly, carpooling and telecommuting levels remained stable. Trip reductions were most significant for school, shopping, and dining purposes, whereas work and social trips were less affected. The study concludes that variable tolling effectively reduced congestion on SR-520 and improved traveler satisfaction regarding speed and reliability. Post-tolling respondents reported higher commute satisfaction and lower stress levels, with attitudes shifting slightly in favor of tolling. However, opinions on whether tolling improved regional travel were divided: SR-520 users generally viewed the program favorably, while I-90 users, including those who diverted from SR-520, assessed it unfavorably. The findings also highlight potential equity concerns, as lower-income households reduced travel more significantly than higher-income groups, though the latter paid more in tolls. This research provides empirical evidence on the behavioral responses to full-facility congestion pricing, offering insights for future transportation policy and demand management strategies.

Key finding

SR-520 experienced a 43% reduction in recorded trips and a 52% drop in vehicle-miles of travel following the implementation of variable tolling, with significant diversion to the toll-free I-90 alternative.

Methodology

survey

Sample size: 2000

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.

• traffic density

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: observational prevalence