BOTHELL, Wash. – Tuesday marks one year since tolling started on Interstate 405.

The 17-mile stretch allows drivers to pay to use the HOV lanes, and carpools in that area were changed from two people to three people.

“In that one year, we’ve seen that express toll lanes are doing what they’re intended to do. They’re providing a faster, more predictable trip,” said Emily Pace, a spokesperson for the WSDOT tolling division.

WSDOT has also started collecting high tolls more often. Data from WSOT shows the number of days when toll lanes cost $10 has increased in recent months.

December 2015 – 6 days
January 2016 – 8 days
February 2016 – 9 days
March 2016 – 15 days
April 2016 – 15 days
May 2015 – 18 days
June 2016 – 21 days
July 2016 – 19 days
August 2016 – 20 days

WSDOT said the average length of time $10 has been displayed is 52 minutes, and the median 45 minutes.

WSDOT claims about 2/3 of drivers are using the lanes about once a week when they need it. It counted 12 million trips in the first 10 months. WSDOT says the toll cuts 10 to 15 minutes off the commute for drivers who use the lanes, and it’s helped shave off three to six minutes in other lanes in most places.

David Hablewits of says that’s more to do with other added lanes, not the toll lanes.

“The problem they have to deal with is they have to add capacity,” Hablewits said. “How to get people out of their cars. Charging them money doesn't get them out of their cars.”

WSDOT projects it will make $20 million net profit from last year’s opening day to next June. Some of that money will go to adding a shoulder lane northbound north of Bothell during peak commute hours.