You’ll soon get to use some new pieces of I-5, but congestion relief could be years away

Big changes are coming to the Interstate 5 commute through Tacoma this year, but don’t hold your breath for immediate congestion relief, especially southbound. That might not come until 2021.

The first change could come as soon as next week.

That’s when officials with the state Department of Transportation expect to open a ramp from northbound I-5 onto northbound state Route 167, also known as River Road.

The new ramp is longer and straighter, eliminating a sharp turn that often led to slowdowns and sometimes wrecks.

“This is really going to be nice,” said Tim Wasson, a Transportation Department field engineer, as he inspected the ramp near the Emerald Queen Casino.

Opening the new ramp and closing the old one also will clear space for Hamilton Construction Co. crews to build the northbound I-5 alignment that will carry traffic via a new bridge over the Puyallup River.

“That is a big milestone,” said Brenden Clarke, the Transportation Department project engineer helping to oversee a $261 million project that includes the new bridge.

Hamilton crews must close the current ramp, which carries about 13,000 cars a day, from I-5 to Route 167, to complete the work. That closure is scheduled 10 p.m. Friday (Feb. 3) to 4 a.m. Monday (Feb. 6).

The new ramp could be open to traffic Monday if all goes well and the weather cooperates, Clarke said.

Other changes slated for this year include opening the new Puyallup River bridge and shifting northbound traffic onto another new bridge over Interstate 705 near the Tacoma Dome.

Both projects are expected to help ease traffic through a notoriously congested part of the city.

Clarke said the new northbound Puyallup River bridge will be wider than the current one and that the new approach is straighter.

“It’s a much smoother curve,” he said. “The current bridge is narrower. As people come onto it, they just naturally slow down.”

One note about the new bridge: The northern terminus is quite a bit lower than the huge earthen berm onto which it will connect.

That was by design, said Lone Moody, another state engineer.

Extra fill was deposited on top of the berm to help compact the soil beneath, she said.

When crews are ready to connect the bridge to the berm, they will excavate the extra soil so the bridge deck and berm top are at the same grade, Clarke said.

That work could start in April, with traffic using the new bridge by the end of the year, although finishing work might drag into 2018.

Northbound drivers should be traveling on the new I-5 bridge over I-705 by early June, said Les DuBois, a state field engineer overseeing that project.

Crews are preparing the new lanes approaching that bridge, as well as the lanes on the other side, DuBois said, but the bridge is ready.

That work is part of a separate $161 million program that will add carpool lanes through that stretch of I-5 and replace pavement that is decades old.

Opening the new bridges will allow crews to begin concentrating on the southbound lanes between Port of Tacoma Road and South M Street.

That work, which will entail numerous lane shifts and other changes, will extend the pain of drivers already suffering through heavy afternoon traffic most days.

Transportation Department engineers are sympathetic, but point out that more than 200,000 vehicles travel I-5 past the Tacoma Dome each day. Completing a major construction project while trying to accommodate that number of cars is challenging, they said.

One of the biggest changes will be splitting southbound traffic into two segments, one continuing toward Lakewood and the other heading for exits to I-705, westbound state Route 16 and South 38th Street, said Cara Mitchell, a Transportation Department spokeswoman.

The segment continuing south toward Lakewood will be diverted onto the existing northbound lanes. The segment heading toward I-705, state Route 16 and South 38th Street will be funneled onto two lanes on the existing southbound lanes.

“Drivers are going to have to pick those lanes way back by Portland Avenue,” Mitchell said. “Advanced signage will be installed telling drivers of the change as far back as Port of Tacoma Road.”

That switch is expected this spring.

The new configuration will allow crews from Max J. Kuney Co. to replace old pavement on southbound I-5 from Portland Avenue to South M Street. Traffic will be diverted across the lanes as the work progresses.

“It will make room for crews to get in there and get at that existing pavement,” DuBois said.

It also will allow for the start of a third project in the area, a $218 million program to build the so-called “connectors” and associated bridges and other structures needed to connect carpool lanes on I-5 and state Route 16.

That project will build a third and final viaduct through the Nalley Valley, add direct-access carpool ramps connecting I-5 and state Route 16, and realign I-5 in both directions between 48th and M streets to accommodate it all.

Construction on that project should start next month, with a finishing date slated for early summer 2019, said Troy Watts, a state field engineer.

Watts said drivers can expect delays during that work, which will require more lane shifts and other traffic-snarling work.

“They can keep on hating me for a few more years,” he said.

There’s more.

In 2018, crews are scheduled to begin demolition and rebuilding the south I-5 bridge across the Puyallup River. That work will last until 2021.

State project engineer Gaius Sanoy said the pain will be worth it when everything is said and done, opening carpool lanes from King County through Tacoma on I-5 and state Route 16.

“When this is all done, what you’ll get is seamless connectivity of the HOV system,” Sanoy said.

In other words: No pain, no gain.

Adam Lynn: