Vancouver region State Route 14 - Throughput
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Measures of throughput productivity on the SR 14 corridor in the Vancouver area
Throughput productivity
Throughput productivity measures how efficiently existing highway capacity is being used. It can be reported for vehicles or travelers, making it a very adaptive metric. WSDOT uses the maximum throughput standard to assess travel delay relative to a highway's most efficient speed, which is 85% of the posted speed limit.
Lost throughput productivity is the percentage change of highway throughput in respect to maximum throughput due to congestion and other events that cause vehicles to travel below a threshold speed. See WSDOT's how to calculate throughput productivity (PDF 5.9MB).
In order to gauge the lost productivity on I-5, I-205, and SR 14 in the Vancouver region, WSDOT analyzed vehicle throughput at three locations: I-5 near Fourth Plain Boulevard (MP 1.4), I-205 near 10th Street (MP 28.0), and SR 14 near Lieser Road (MP 4.5).
Sources: WSDOT Transportation Safety and Systems Analysis Division and WSDOT TRACFLOW (https://tracflow.wsdot.wa.gov/)
Note: Source data collection devices were updated in 2017.
Multi-year trends
Throughput productivity remained steady between 2020 and 2022.
In 2020, due to the statewide response to COVID-19, there was no drop in vehicle throughput.
WSDOT measures throughput productivity on SR 14 at South Lieser Road. This location did not experience any loss of westbound throughput productivity at any point from 2018 to 2019. The eastbound direction experienced minor evening throughput productivity losses.
Annual highlights
In 2022, there were no significant changes in throughput productivity compared to 2021: There was no throughput productivity loss at SR 14 near South Lieser Road in either direction throughout the day.
In 2021, there were no significant changes in throughput productivity compared to 2020: There was no throughput productivity loss at SR 14 near South Lieser Road in either directions throughout the day.
In 2020, due to the statewide response to COVID-19 there was no drop in vehicle throughput.
In 2020 and 2019, vehicle throughput at SR 14 near South Lieser Road ranged from 80% to 100% of maximum throughput at their most congested times. Throughput productivity varies by direction of travel, location and time of day. For example, traveling westbound, throughput productivity at this location in 2020 and 2019 was at 100% and no throughput productivity loss was experienced.
In 2019, vehicle throughput at SR 14 near South Lieser Road ranged from 80% to 84% of maximum throughput at their most congested times. Throughput productivity varies by direction of travel, location and time of day. For example, traveling westbound, throughput productivity at this location in 2019 was at 100% and no throughput productivity loss was experienced.
In 2018, vehicle throughput at SR 14 near South Lieser Road was at 87% of maximum throughput at their most congested times. Throughput productivity varies by direction of travel, location and time of day. For example, traveling westbound, throughput productivity at this location in 2018 was at 100% and no throughput productivity loss was experienced.