Drivers on I-405 have been watching weekday drive times ever since the state implemented a new tolling system in September. Now there’s news for that weekend driver, and it’s not all good.

“What drivers have been telling us is true &#8212 weekend congestion has increased since the I-405 express toll lanes opened,” the Washington State Department of Transportation posted on its blog.

WSDOT’s blog notes that between Oct. 3 and Nov. 8 weekend drive times rose by about 5 minutes, depending on the time of day. It was up by 10 minutes in the northbound lanes at peak times on Saturdays. WSDOT notes a few factors that could have caused this, including lane closures for construction; higher traffic for sporting events; and the rainfall that Bellevue has experienced recently.

Related: Traffic is so bad that King County will pay you to abandon I-405

“On top of all that, we’re still seeing fewer drivers in the express toll lanes on weekends,” WSDOT states in its blog. “All of this adds up to impacts for regular lane drivers.”

Sunday drive times have increased &#8212 by about 5 minutes at the most &#8212 and the average drive time between Bellevue and Lynnwood is about 15-20 minutes.

But Saturdays have taken the biggest hit. In 2014, the average drive time along I-405 on a Saturday was about 15-20 minutes between Bellevue and Lynnwood. WSDOT now says that Saturday drive times have increased by an average of 5-10 minutes in both directions.

“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,” WSDOT states.

Tell us about what slows you down

Fewer people are using the express toll lanes during the weekend this year, than were using the HOV lane last year, according to WSDOT. Though more weekday drivers are utilizing the express toll lanes, weekend drivers aren’t jumping in. WSDOT officials believe there are families and others with multiple passengers on I-405, but that they don’t have a Flex Pass. That would explain why some are not using the express toll lanes on the weekends.

The department says that it will take up to year for drivers to fully adapt to the new tolling system on I-405.