Central Puget Sound High Occupancy Vehicle - Reliability
On this page:
Measures of HOV network speed and reliability in the central Puget Sound region
HOV reliability
The speed and reliability performance standard for freeway HOV lanes was adopted by WSDOT and the Puget Sound Regional Council in 1991. The standard states that travelers in the HOV lane should be able to maintain an average speed of at least 45 mph 90% of the time during the peak hours of travel. For details on the methodology used to calculate HOV Reliability, refer to WSDOT's Handbook for Corridor Capacity Evaluation (PDF 5.9 MB).
Even when performance is reduced during congested periods, HOV lanes still generally provide speed and reliability benefits over adjacent GP lanes. During off-peak times of the day, all HOV corridors generally meet the standard.
I-405 ETL/SR 167 HOT Performance: I-405 ETL commutes between Lynnwood and Bellevue are not reported in this section, as they have separate legislatively-mandated speed and reliability performance measures and reporting requirements (per RCW47.56.880). For consistency, WSDOT follows the same reporting guidelines for the SR 167 HOT lanes. For the most up-to-date performance information on the I-405 ETLs and the SR 167 HOT lanes, refer to WSDOT's Toll Division Annual Reports at www.wsdot.wa.gov/tolling/publications.htm.
Sources: WSDOT Transportation Safety and Systems Analysis Division and WSDOT TRACFLOW (https://tracflow.wsdot.wa.gov/)
Performance highlights
In 2023, seven of the ten monitored HOV commute routes failed to meet speed and reliability standards, up from six in 2022. The underperforming routes included:
- Northbound and southbound I-5 commutes between Seattle and Everett as well as Seattle and Federal Way
- Northbound and southbound I-405 commutes between Bellevue and Tukwila
- Morning westbound SR 520 from Redmond to Bellevue
Notably, the southbound I-405 route from Bellevue to Tukwila scored only 8%, down from 14% in 2022.
Seven of the 10 HOV commute routes monitored did not meet the HOV standard for speed and reliability performance in 2023, a decrease compared to six corridors in 2022. The seven routes that did not meets standard were:
- The morning and evening northbound and southbound I-5 commute between Seattle and Everett,
- The morning and evening northbound and southbound I-5 commute between Seattle and Federal Way
- The morning and evening northbound and southbound I-405 commute between Bellevue and Tukwila
- And the morning westbound SR 520, Redmond to Bellevue.
Of these seven corridors, I-405 Bellevue to Tukwila in the southbound during the evening commute scored the lowest (8%) compared to 14% in 2022.
In 2021, five of the 10 HOV commute routes monitored met the HOV standard for speed and reliability performance. This is an increase compared to three corridors in 2020. The five corridors that met the speed and reliability standards were: the evening SR 520 eastbound commute from Bellevue to Redmond, I-90 eastbound commute Seattle to Issaquah, morning I-5 southbound commute from Everett to Seattle, I-90 westbound commute from Issaquah to Seattle, and I-405 northbound commute from Tukwila to Bellevue. Amongst these five corridors, I-405 Bellevue to Tukwila in the southbound during the evening commute scored relatively low compared to 2020.
In 2020, due to the statewide response to COVID-19 many commute routes increased reliability performance compared to the previous year. Three of the 10 HOV commutes monitored met the HOV standard in 2020 for speed and reliability performance, up from one corridor in 2019. The three corridors that met the speed and reliability standard in 2020 were the evening SR 520 eastbound commute from Bellevue to Redmond, the morning I-90 westbound commute from Issaquah to Seattle, and SR 520 westbound commute from Redmond to Bellevue. Other commutes got relatively high scores compared to previous years ranging between 77% and 89%.