EVERETT — With the click of a mouse, drivers can check on traffic along I-5 from Arlington almost to Tacoma — except for one stretch.

That five-mile section is between Everett and Marysville. It turns up gray on the state traffic website, meaning no information is available because there’s

no equipment.

No car-counting sensors are planted in I-5 on that stretch and no cameras are mounted along the shoulder, either for the public or state Department of Transportation staff to see what’s going on there.

“We’re basically blind,” said Bronlea Mishler, a spokeswoman for the department. “We tend to have collisions in that little flat stretch there by the lumber mill. We can’t see them and have to rely on the State Patrol to tell us what’s happening.”

That’s changing soon. State crews plan to install traffic-counting loops in the road and six cameras on that stretch. The state’s cameras are only to provide footage and are not used to enforce traffic laws.

The fiber-optic lines for the new cameras also will allow the state to activate 12 other cameras already installed farther north.

State transportation staff use the cameras to verify information about reported incidents and relay it to the public. The traffic-counting loops essentially count the cars and send the information to color-coded maps on the state’s web page that show the level of congestion along that stretch of road.

When the project is done, more complete traffic flow information will be available on the state’s website, and transportation staff will be able to report incidents on that stretch to the public much more quickly.

“There’s such a growth of traffic around Marysville, it will be nice to have the responsiveness we don’t have right now,” Mishler said.

The $1.1 million for the electronics is part of a $3.1 million project that includes repaving southbound I-5 between Marysville and Everett. The roadway has developed ruts from the 157,000 cars and trucks driving over it daily. The repaving is expected to be done by this fall and the electronics are scheduled to be up and running by the end of the year.

Currently, cameras are situated at I-5 and E. Marine View Drive in Everett and at the I-5 bridge over Ebey Slough in Marysville, but none in between.

The E. Marine View Drive camera was the last one installed as the system made its way north. That camera can be remotely swiveled and pick up views to the north or south, but can’t see much past about a mile north.

The Ebey Slough camera is an older, standalone model connected to the web but not to the transportation department’s headquarters in Shoreline. It can’t be adjusted, providing information only for a short distance looking south.

“If something happens in front of the camera, great, otherwise, we’re out of luck,” Mishler said.

Road loops and cameras were installed farther north, on I-5 between downtown Marysville and the Stillaguamish River, last year. This was done as part of an $18.9 million project to install concrete barriers along the I-5 median in that stretch after cable barriers failed to prevent several fatal crossover collisions from 2000 to 2007. An analysis of accident data by The Herald found that the cables were failing to stop cars in the median 20 percent of the time along a three-mile section.

While the road loops installed along with the concrete barriers are providing information to the web page, the cameras aren’t yet hooked up to the state’s system. The fiber optic lines are in place but can’t be connected until new lines are installed along with the new cameras between Marysville and Everett, Mishler said.

So when the project is done, 18 cameras will come newly on-line.

Currently in Snohomish County 36 cameras are operative on I-5, with about half of them accessible on the web.

Overall, only about one-third of the state’s cameras may be found on the website because the number of icons would crowd the map, Mishler said.