South Puget Sound Interstate 5 - Delay
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Measures of delay on the I-5 corridor in the south Puget Sound region
Travel delay
Travel delay is the amount of extra time spent at speeds below a given threshold—such as the posted speed limit or the maximum throughput speed on a highway. WSDOT uses maximum throughput speed (85% of posted speed limit) as its threshold for calculating delay, which it measures in either annual hours of delay per vehicle or annual hours of delay per person. For details on methodology to calculate travel delay, see WSDOT's Handbook for Corridor Capacity Evaluation (PDF 5.9MB).
Heat maps
The heat maps below show vehicle hours of delay by time of day (measured in 5-minute intervals) and milepost. The darker the shading in a particular spot on the heat map, the more hours of delay occurred at that time and place. Shading is standardized across all the corridors to allow for comparison.
There is a separate heat map for each direction of travel. The eastbound graph below is read from left to right, while the corresponding westbound graph is read from right to left. For additional details on how to read heat maps, see Handbook for Corridor Capacity Evaluation (PDF 5.9MB).
Sources: WSDOT Transportation Safety and Systems Analysis Division and WSDOT TRACFLOW (https://tracflow.wsdot.wa.gov/)
Multi-year trends
In 2022, vehicle delay decreased compared to 2021 due to the completion of major roadway construction in the Tacoma Dome vicinity . The speed limit, which was reduced to improve safety during the construction work, returned 60 mph, and widen street contributed to fewer delays in these sections.
In 2021 delay increased compared to 2020 due to the recovery of traffic volume in the wake of COVID-19.
In 2020, due to the statewide response to COVID-19, there was a significant decrease in delay compared to previous years. The 2020 delay decreased even through the Tacoma Dome and Federal Way compared to 2019.
The south Puget Sound region experienced more delay in 2019 than in 2018 at nearly every location along the corridor. The exception was northbound at the Tacoma Dome, which saw slightly less delay in 2019 than 2018. New HOV lanes opened on the I-5 and SR 16 interchange in November 2019, helped with safety, improved mobility and reduced congestion in Pierce county.
Annual highlights
In 2022 vehicle delay decreased by 27% compared to 2021. Vehicle delay on I-5 in the south Puget Sound region occurred in the same locations as in 2021. The most intense vehicle delay on the I-5 corridor occurred between southbound Federal Way and around Fife. The northbound delay from 5 a.m. to 6 p.m. in 2022 was less than the southbound delay between 1 p.m. and 8 p.m. The northbound delay decreased by roughly 76% compared to 2021, while the southbound delay decreased by roughly 10% compared to 2021.
In 2021 delay increased compared to 2020 but still significantly lower compared to pre-pandemic levels. Vehicle delay on I-5 in the south Puget Sound region occurred in the same locations as in 2020. The most intense vehicle delay on the I-5 corridor occurred between Lakewood and around the Tacoma dome. The delay northbound from 5 a.m. to 6 p.m. in 2021 was less than the southbound delay between 1 p.m. and 8 p.m.: the delay northbound increased by roughly 156% compared to 2020, while the delay southbound decreased by roughly 129% compared to 2020.
In 2020, due to the statewide response to COVID-19 there was a significant decrease in delay compared to previous year. Vehicle delay on I-5 in the south Puget Sound region occurred in the same locations as in 2019, but less of it. As in 2019, the most intense vehicle delay on the I-5 corridor occurred between the Tacoma Dome and Federal Way. The delay northbound from 5 a.m. to 7 p.m. in 2020 was less than it was in southbound delay between 2 p.m. and 8 p.m.: the delay northbound decreased by roughly 79% compared to 2019, while the delay southbound decreased by roughly 72% compared to 2019.
In 2019, vehicle delay on I-5 in the south Puget Sound region occurred in the same locations as in 2018, but there was slightly more of it. As in 2018, the most intense vehicle delay on the I-5 corridor occurred between the Tacoma Dome and Federal Way. The delay northbound from 5 a.m. to 7 p.m. in 2019 was more severe than it was southbound delay between 2 p.m. and 8 p.m.: the delay northbound increased by roughly 38% compared to 2018, while the delay southbound in the morning increased by roughly 20% compared to 2018.
In 2018, vehicle delay on I-5 in the south Puget Sound region occurred in the same locations as in 2017 and the delay was unchanged. As in 2017, the most intense vehicle delay on the I-5 corridor occurred between the Tacoma Dome and Federal Way. The delay northbound from 5 a.m. to 7 p.m. in 2018 was more severe than it was southbound between 2 p.m. and 8 p.m.