After a long 13 years, the Novato Narrows stretch of Highway 101 won’t be living up to its name.

The busy segment between Petaluma and Novato is going to be a six-lane freeway after seemingly endless construction is completed this summer.

As that milestone nears, traffic planners in Marin and Sonoma counties are working to come up with the right hours for the bi-county contiguous carpool and bus lanes, which will soon stretch 52 miles, from Windsor to the Richardson Bay Bridge.

Right now, the express-lane hours in the two counties are different.

The change under consideration would extend those weekday hours to 5 to 10 a.m. and 3 to 7 p.m.

But analysis of these hours is showing they could cause traffic problems in Marin.

Afternoon northbound traffic at the Tamalpais Drive exit in Corte Madera and morning southbound flow at San Rafael’s North San Pedro Road are two possible troublespots that are worrying planners.

The goal is not one of relocating the traffic jams, but to keep traffic moving.

For years, the times for lanes dedicated to high-occupancy vehicles have been 6:30 to 8:30 a.m. southbound traffic and 4:30 to 7 p.m. for northbound traffic.

The proposed hours would be a big expansion of those times when the lanes are reserved only for buses and carpools. Those are hours when the lanes are off limits to other motorists, predominantly those traveling solo.

The primary objectives of the lanes have been to speed up travel for transit and carpoolers and create a timesaving incentive for more people to choose those modes of getting up and down Highway 101.

The lanes also remove that traffic from the other lanes and are available to all traffic during noncommute hours and on weekends.

It makes sense to focus on uniform times for the 52-mile stretch.

Criticism of Marin’s more narrow hours of operation has been, particularly during the morning commute, that non-HOV motorists start using the lane at 8:30 a.m. and slow down buses that are still making the commute, carrying workers to their job sites.

The Metropolitan Transportation Commission, in the past, has advanced a proposal to make Bay Area HOV hours uniform through the region.

Marin has balked at that idea, but Marin Supervisor Eric Lucan, the chair of the Transportation Authority of Marin, has urged local officials to be “flexible.”

“We need to have the flexibility to at least put forward some thoughts and recommendations,” he said at a recent TAM meeting.

Officials want to get this matter resolved before the new lanes on the last leg of the freeway widening are open to traffic.

There’s good reason to be flexible. It certainly is time to take a fresh look at the hours with the goal of coordinating the 52-mile stretch and updating them to reflect current commute patterns.

For instance, the afternoon commute jam has been occurring a lot earlier than 4:30.

It also makes sense to tap the brakes on the longer hours as they appear to create more problems than they solve.

TAM officials are also considering turning on metering signals at freeway onramps in Marin. In many places, the signals have already been installed, but not been activated. It’s time to put them to use at onramps where they make sense and won’t be backing up traffic onto city streets.

Running tests on their use at various onramps should be factored into the decision.

The ultimate decision will be made by Caltrans, but TAM is right in coming up with a recommendation for possible changes.