Favorable weather and efficient construction work have helped put two major SR-520 traffic construction projects in Redmond on the fast track to completion.

Both the SR-520 widening project, between SR-202 and West Lake Sammamish Parkway, managed by the Washington State Department of Transportation (WSDOT) and the Northeast 36th Street Bridge project by the City of Redmond could very well be completed by the end of the year.

A well-engineered, landscaped, off-set lid bridge that spans SR-520 in Overlake should be open by late fall — ahead of the initial December deadline, according to Ron Grant, City of Redmond Public Works assistant director. The bridge is being built in the shadow of Microsoft Corp., which has donated $17.5 million toward the $30.5 million project.

“The progress that we’ve been able to make over the winter to get this going makes us more confident we can deliver this in a very timely manner,” Grant said. “We believe that by late fall, this will be open to traffic. … The contractor has done such a great job and the weather has been cooperative. It’s looking pretty good.”

The 520 widening project, between 202 and West Lake Sammamish Parkway, is also moving along smoothly, according to WSDOT project manager Hien Trinh, who said that the contractor, PCL Construction, is planning to finish ahead of the March 2011 deadline, “perhaps as soon as late 2010.”

“Good weather has played a role in allowing the contractor to get certain activities, like paving, striping, earthwork done in a more efficient, timely manner,” Trinh said. “This definitely is a plus in the contractor’s pursuit of an early project finish. … Early completion is a goal that both the contractor and WSDOT shared so I am hopeful that we achieve it.”

Elaborate bridge

Tri-State Construction of Bellevue is the contractor for the Northeast 36th Street Bridge and currently the crew members are working on the large, trapezoid-shaped bridge deck and both the east and west bridge approaches.

Last month, a monumental part of the project was completed when concrete for the west half of the bridge deck was poured — “a massive undertaking,” Grant said.

During the 13-hour work day, 750 cubic yards of concrete, provided by Redmond-based Cadman Inc., was poured, according to Grant. Concrete for the other half of the bridge deck will be poured later this month. Once the deck is poured, workers will install an intricate, extremely tight waterproof system that will seal the bridge, transport the rain and storm water into the city drain systems and not allow water to leak onto 520, Grant said.

When completed, the 480-foot long overpass will accommodate a two-lane road including bike lanes, sidewalks, lighting, utilities, landscaping and a roundabout at the east approach. The area around Northeast 31st Street and 152nd Avenue Northeast is closed during construction as crew members have re-graded the area and are working on building the city’s first roundabout. In addition, the overpass provides a connector to the bike trail that runs along 520.

City officials, including Mayor John Marchione, say this bridge will help decrease traffic congestion and improve mobility in the Overlake neighborhood, which has been designated as an urban growth area, with several new housing, retail and commercial developments slated for the neighborhood in the coming years.

“The 36th Street Bridge will greatly enhance mobility in the Overlake business district,” Marchione said. “People will be able to travel east and west without going through two of our most congested intersections of (Northeast) 40th Street and 156th (Avenue Northeast) and (Northeast) 24th Street and 148th (Avenue Northeast). In turn, this project should provide some relief at the 148th (Avenue Northeast) and (Northeast) 40th Street off-ramps of SR 520.”

The bridge will also help make improve access to the Overlake Transit Center/Park and Ride on the east side of 520 adjacent to Microsoft. In addition, the project has created enough room underneath the bridge for light rail, which has a planned route to the Overlake Transit Center.

Improving safety along 520

The many pockets of orange construction fences can’t be missed while drivers head into Redmond on 520, as crews are working to widen the highway from two to four lanes by adding a merge lane and a carpool lane in both directions. The $71 million widening project is “expected to reduce congestion. … Better traffic flow usually translates to increased safety because drivers aren’t encountering unexpected backups,” Trinh said.

Widening 520 will reduce peak morning commute times by 60 percent and reduce peak evening commute times by 75 percent, according to the WSDOT Web site. In addition, it will eliminate the existing single-lane bottleneck between 202 and Avondale Road.

As part of the widening project, new, safer on and off ramps to 520 will be built. The new West Lake Sammamish Parkway on-ramp to eastbound 520 was recently opened and is “working well,” Trinh said.

“The new configuration is better from a driver’s perspective because the merge point is more visible and drivers can see further down the highway. It also gives them more distance to get up to freeway speed.”

Currently, crew members are working on the new westbound 520 off-ramp to West Lake Sammamish Parkway, according to Trinh, who said that the new off-ramp should be completed by mid-August.

There have been several lane closures during the project and there are more coming, Trinh said.

“The next planned weekend closure is the westbound SR 520 off-ramp to West Lake Sammamish Parkway on April 17-18,” he said.

In addition, Trinh said the eastbound SR 520 on-ramp from Northeast 76th Street — the last on-ramp on 520 before it turns into Avondale Road Northeast — is currently closed and will be closed for the next 40 days for construction of a retaining wall.

“The detour is fairly simple and we don’t anticipate major congestion as a result,” Trinh said.

End result: ‘Good circulation’

There’s no question all of this construction along 520 has created inconvenient detours, lane closures and even more traffic congestion, Grant said, but in the end, Redmond will get the traffic relief it desperately needs.

“These kinds of projects can be painful,” Grant said. “We understand it is challenging for people because of the construction zones, but they are all being done for a purpose and that is to provide a better project in the end.”

Marchione said these are just two of many other construction projects coming to Redmond to help improve traffic congestion and increase mobility.

“The city is obtaining excellent prices for construction at this time and that allows our dollar to go further,” he said. “But there is still a ways to go. At the base of Old Redmond Road we want to install a traffic light in the next 18 months or sooner. In May, we begin construction on extending 161st Avenue (Northeast) in downtown to add to the street grid. We plug away at it as we head to a goal of a more pedestrian-friendly transportation system that allows for good circulation between and within Redmond neighborhoods.”