A new shoulder lane on northbound Interstate 405 has helped speed the evening commute in its first two weeks. Now, drivers hope those quicker travel times become a trend.

The Washington State Department of Transportation (WSDOT) on April 24 opened up 1.8 miles of the right-hand shoulder, from State Route 527 to the Interstate 5 interchange. Drivers can use the shoulder when electronic signs indicate it’s OK. State employees monitor traffic conditions and remotely open the lanes when congestion gets heavy.

In the first four days of operation, drivers saw travel time improvements of between 5 minutes and 15 minutes, depending on how far they went, said Craig Smiley, a WSDOT spokesman.

“However, it is too soon to tell whether these trends will hold for the long-term,” Smiley added.

Traffic volumes were lighter than normal across the region last week, he noted.

On average, about 1,000 vehicles per hour used the shoulder lane the first four days, Smiley said. Perhaps not coincidentally, that’s the same number that merge onto northbound I-405 from SR 527 during peak periods.

The northbound commute got longer after the state widened the interstate south of State Route 522 as part of its toll project. Five lanes of traffic are now funneled into three as drivers cross the line into Snohomish County.

Opening up the shoulder adds a fourth lane for the evening rush.

“Instead of stop and go, it’s been 60 mph,” said Beth Lahore, who gets on at SR 527 on her trek back to Smokey Point. “Instead of taking 30 minutes to go six miles it takes about 10 minutes to get to I-5.”

It’s a breath of fresh air that she hopes lasts into the coming months.

“I haven’t seen the toll lanes help anything over that span,” she said.

The faster travel times showed up in toll rates.

Tolls last week were down from the usual $10 maximum to $7 coming from Kirkland, noted Peter Moreno, who commutes with his wife from the Eastside to their Marysville home.

“I have noticed the toll lanes run a tad slower through Bothell and the general purpose lanes are running quicker,” he added.

The improvement may have shifted some of the backup, however.

“We used to cruise onto I-5. Now it has been backed up quite a bit. I can only assume it is because the shoulder is allowing more cars to get to I-5 quicker,” Moreno said.

Jeff Yirak, of Snohomish, took the SR 527 exit on his way back from Bellevue. “I do see a great improvement,” he said.

Before, he was getting off earlier, at 195th Street, to avoid the bumper-to-bumper congestion that frequently materializes at SR 522.

It’s the latest shift in his commute since tolling began.

Yirak used to carpool. When the state added tolling, he and his carpool buddy found a third person to qualify for toll-free travel in the express toll lane. But it proved difficult to coordinate.

“The hassle of picking up carpoolers wasn’t worth the savings to use the (express toll lanes) for free. Instead, I just go solo, pick a smart route, and pay,” Yirak said.

That includes paying a toll in the southern section where there are more lanes, including two toll lanes.

State planners say they’re not finished with the northbound commute. They eventually plan to widen the interstate there by extending the second express toll lane north of SR 522. Interchange improvements also are on the to-do list. But the big-ticket projects are years off.

Meanwhile, a similar shoulder lane is planned for the northbound I-5 commute to Marysville.

Melissa Slager: streetsmarts@heraldnet.com; 425-339-3432.

A new shoulder lane helped the evening commute on northbound I-405 through Canyon Park during its first week. Shown is a state map showing traffic conditions through the area at 5 p.m. April 19, and the same area a week later when the shoulder was open to drivers. (WSDOT traffic maps)