Concrete barriers backed for problem stretch of I-5

A troublesome section of Interstate 5 north of Everett may soon have concrete barriers to stop traffic from crossing over one side of the freeway to the other.

That is a recommendation in a report to be released next week.

The concrete barriers, which would replace the cable barriers in the northbound lane, would augment cable barriers that were installed to keep southbound cars from veering off the road.

While cable barriers have stopped cars from crossing the freeway, they aren't always successful.

Gov. Christine Gregoire in February ordered the independent review of freeway cable median barriers after a fatal accident Feb. 13 on I-5 near Marysville.

A southbound vehicle ripped through two sets of cable barriers and collided with a charter bus, leaving the driver dead and another person injured.

The state says it hopes to put concrete barriers on the northbound I-5 inside shoulder to stop southbound cars from going under or over the median cable barrier and colliding with northbound traffic.

"First you'll encounter the cable and it will arrest you without deflecting you back in traffic," said Doug MacDonald, DOT secretary. "But if the car overrides the cables, before you head into the northbound lanes, you'll hit the back of the Jersey barrier."

He compares it to a belt and suspenders, where the concrete barrier will be the ultimate line of defense against a head-on crash in the northbound lanes.

MacDonald said the problem with I-5 north of Everett is southbound traffic that must suddenly slow down when approaching the shopping centers and casinos near Marysville, as well as the slowing Everett traffic. Northbound traffic doesn't have the same problem because cars are moving into a less-congested highway, he said.

By the end of 2006, there were 138 miles of cable median barriers on state highways, with another 50 miles scheduled to be completed this year.

Lorena Eng, the DOT's Northwest regional administrator, said 96 percent of the vehicles that struck cable median barriers between 1999 and 2005 were contained entirely by the barrier system. In 2006, the barriers on I-5 in Marysville contained 33 of 34 reported collisions; motorists walked away uninjured in 27 of the accidents.

But even while the DOT claims success, a recent department study also found that 18 vehicles passed through the cables between Arlington and Marysville from 1999 to 2005.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com