OLYMPIA — Congestion is lengthening commutes for carpool lane users in the Puget Sound region and state transportation officials are searching for ways to get them traveling faster.

One way might be to crack down on lane violators through greater enforcement by the Washington State Patrol and heftier fines for offenders, agency officials told the Senate Transportation Committee on Monday.

Another is to harden more stretches of highway shoulder for buses to use in the peak hours, as now happens on a stretch between Lynnwood and Mountlake Terrace, the state Department of Transportation officials told the panel.

And a third idea is to consider putting in “buffers” separating high occupancy vehicle lanes and regular lanes to combat the issue of carpool users slowing down when the other lanes are clogged even if theirs is not.

The long-term goal is figuring out how to reduce demand in those lanes, which means figuring out how to reduce the number of vehicle lanes, explained John Nisbet, a state traffic engineer.

Monday was a work session in which Nisbet and Robin Mayhew, director of the management and mobility for the transportation department, provided lawmakers with a snapshot of the challenge with the roughly 250 miles of HOV lanes in the Puget Sound region. Their presentation did not delve into any issues surrounding the I-405 express toll lanes between Lynnwood and Bellevue.

Overall, congestion on the central Puget Sound region’s major roads is up by more than 22 percent over the past two years, according to the agency’s 2017 Corridor Capacity report.

Carpool lanes are getting clogged and not performing up to state and federal standards.

The goal in these HOV lanes is to move traffic through at least 45 mph, 90 percent of the time during peak hours. From Everett to Seattle on I-5, that goal was only met 19 percent of the time southbound for the morning commute and 21 percent northbound for the evening commute.

From Federal Way to Seattle on I-5, it was just as bad: 18 percent going north in the morning and 21 percent southbound for evening commute. And travel in carpool lanes between Tukwila and Bellevue on I-405 also fared poorly, meeting the goal just 24 percent going northbound in the morning and 18 percent southbound on the evening drive home.

In all, 10 of 12 stretches of HOV lanes regularly monitored by the state failed to meet the standard, according to Monday’s presentation. The two exceptions involved travel between and Issaquah and Seattle on I-90. Commuters enjoyed speeds of at least 45 mph 97 percent of the time westbound in the morning and eastbound in the evening.

Mayhew mentioned the potential for increasing enforcement and updating the fine structure but did not reveal any details of what is being considered. She said the agency will team up with the Puget Sound Regional Council to study ways to better manage demand for the lanes.

By the end of the year, she said she hoped be able to provide lawmakers with a clearer long-term strategy.

“It’s very clear the HOV facilities need some attention,” she said.

Jerry Cornfield: 360-352-8623; jcornfield@herald net.com. Twitter: @dospueblos.