MARYSVILLE — These aren’t the Jersey barriers one would normally see on a freeway.
They’re bigger — much bigger.
The concrete barriers being installed on I-5 through Marysville are expected to keep drivers safer from crossover accidents on a stretch of freeway that has a deadly reputation.
The large barriers provide the highest level of protection available, state officials say.
“This is called a high- performance barrier,” said Amir Ahmadi, the engineer managing the project for the state Department of Transportation.
The state is installing the barriers along 10 miles of the median on the northbound lanes of I-5 between the Fourth Street exit and the Stillaguamish River bridge. The $18.9 million project is expected to be done by the end of the year.
The barriers will replace the cable barriers on the northbound side while the cables on the southbound side will remain for extra protection.
Eight people died in across-the-median crashes on the stretch between 2000 and 2007. Each time, the cable barriers failed to prevent the collision.
In June 2005, shortly after one of the fatal wrecks, the state reduced the speed limit to 60 mph from 70 mph along that stretch. A second row of cables was added later. The state also hired an independent expert to study what to do about the deadly stretch of highway.
In 2007, the consultant recommended replacing the cable barriers along the stretch of highway with concrete barriers. State officials said cable barriers perform effectively in most areas where they’re used. The study concluded, however, that the cable barriers not only were the wrong tool to use in Marysville, but that they had been improperly installed.
The state last year settled a lawsuit alleging that the cable barriers failed to prevent a deadly crossover crash in 2005. The state agreed to pay $1 million to the children of a couple killed in a crash on I-5 near Marysville, according to court documents.
Now, the state is taking no chances on the stretch, officials say.
The new barriers are 4 feet tall and weigh 8 tons apiece. That compares to standard Jersey barriers, which are just under 3 feet tall and a slightly more than 3 tons, Ahmadi said. The barrier sections are 20 feet long, while most Jersey barriers are 12 ½ feet long.
“We wanted to provide the highest level of protection against crossovers,” said Meghan Pembroke, a spokeswoman for the Transportation Department.
The new barriers will be anchored into the ground with 6 inches of concrete, while Jersey barriers sit on top of the paved surface. The new barriers will extend 42 inches above the ground, which is also expected to reduce glare from oncoming headlights, Ahmadi said.
The Transportation Department is using the larger concrete barriers in several other areas around the state, including the I-405 corridor, Pembroke said.
The larger barriers do have a potential drawback by increasing the damage from impact for vehicles that hit them. There also is an increased chance of vehicles bouncing back into traffic compared to either cable barriers or standard Jersey barriers, officials say.
“That’s an unavoidable trade-off that we have,” Pembroke said.
Crews are working their way north through Marysville and Arlington, with the barriers now extending just beyond the 116th Street NE overpass. When all the barriers are laid down, crews will go back and cement them into the ground.
In addition to the concrete barriers, the project includes new traffic cameras, electronic message signs, traffic sensors along the freeway and storm water treatment features. The state is replacing the soil in the medians, a move expected to provide better drainage and filtration.
Bill Sheets: 425-339-3439; firstname.lastname@example.org.