We’ve written several blog posts examining weekday traffic on I-405, but we’ve heard from a lot of drivers about increased traffic on the weekends, so we took a hard look at the numbers.
What drivers have been telling us is true - weekend congestion has increased since the I-405 express toll lanes opened. Based on data from October 3- November 8, travel times between Bellevue and Lynnwood are generally up to 5 minutes longer throughout the weekend, with up to a 10 minute increase northbound on Saturdays.
There are many factors that affect weekend traffic. There have been many lane closures during these six weekends due to construction, several big-impact sporting events, and of course the rainy weather never helps traffic. According to Accuweather.com archives, there was three times as much rainfall in Bellevue over these weekends than over the same time period in 2014, 3.7 inches this year compared to 1.2 inches last year. On top of all that, we’re still seeing fewer drivers in the express toll lanes on weekends. All of this adds up to impacts for regular lane drivers.
Saturday I-405 travel times have increased by 5-10 minutes on average in the first six weeks since the express toll lanes opened. For this time period in 2014, Saturday average travel times ranged from 15-20 minutes for most of the day in both directions, with the peak late in the day. This year, we saw southbound trips approach 20 minutes much more frequently throughout the day. While the increase has been under 5 minutes for most weekends, a couple of particularly bad days brought up the averages for northbound travel up to 5-10 minutes longer than last year’s average high at times.
Sunday traffic has increased less dramatically, with 5 minute or less increase in average travel times in the afternoons. Last year, Sunday average travel times remained close to 15 minutes for most of the time. Since the express toll lanes opened, average Sunday travel times in both directions crept up by a few minutes, ranging from 15-20 minutes in the afternoons.
Fewer drivers in the express toll lanes
We’re also seeing fewer drivers using the express toll lanes compared to the HOV lanes last year. This is in contrast to weekdays, when the express toll lanes are carrying more vehicles than the HOV lanes previously did. This, combined with weekend storms, construction, and other big events, helps explain the travel times in the regular lanes.
We do have a few observations about why fewer weekend drivers are using the express toll lanes on the weekends:
- We suspect that there are many drivers who carpool with their family or friends on the weekend, but may not have a Flex Pass yet. This makes sense as many weekend carpoolers may not carpool as often as daily commuters, or may not be frequent I-405 drivers at all.
- Weekend drivers might just not be in as much of a rush. We say that the express toll lanes are there when you need them, and maybe people just don’t feel the same need to make it to brunch on time as they do to make it to daycare by 6pm.
- Traffic isn’t bad enough to make the toll worth it. Weekend trips may be 5-10 minutes slower if you’re going the full length from Bellevue to Lynnwood, but they’re still a whole lot less congested than weekday rush hours.
We’ve always said that it takes 6 months to a year for drivers to adjust to the changes, and this is especially true for weekend drivers who may travel or carpool on I-405 less frequently and have had fewer trips then daily commuters to adjust to the changes.
- Carpools with 2 or more people can still drive in the express toll lanes for free with a Flex Pass all weekend long.
- Rideshareonline.com is still giving away free Flex Passes through the end of 2015. Anyone who carpools on I-405 at least once in a typical week qualifies, including weekend trips with your family.
- Every week, more and more drivers continue to get Flex Passes, so we expect more carpoolers to return to the express toll lanes each week.
- Construction closures, events, and weather also have a big impact on weekend traffic, and it has certainly been a busy and wet month. We expect that traffic will calm down when these other factors diminish.