A full timeline of the SR 99 tunnel work since Viadoom began

Jan 29, 2019, 7:08 AM
viadoom, sr 99...
Ironworkers construct epoxy-coated rebar lattice for the road deck of the northbound SR 99 off-ramp near the stadium district. (WSDOT)

We are in the final stretch of the #SeattleSqueeze aka Viadoom. One more week for drivers to change their habits, take transit or flex their schedule until the new replacement SR 99 tunnel under Seattle opens. 

The tunnel is complete, but the ramps into the entrances are currently being constructed. Washington State Department of Transportation updates drivers twice a day on the progress of that work. The questions for commuters are: Will it open on time? And will traffic get worse, or stay the same, when the tunnel does open?

Below are updates from each day since Viadoom began, beginning with the most recent construction on Monday.

Jan. 28

Crews are placing barrier and curb on the new southbound off-ramp to S Royal Brougham Way.

A concrete pour is scheduled on the new northbound off-ramp to South Dearborn Street. At the north portal, crews are wrapping up electrical work.

Jan. 27

Crews spent the weekend placing rebar, building barriers and performing electrical work. Several more concrete pours are scheduled to occur over the next few days.

Jan. 26

There is a lot of concrete curing right now (the process by which concrete hardens to its required strength). At the tunnel’s south end, crews are working on the roadway barriers for the future northbound off-ramp to Alaskan Way.

Jan. 25

Crews working for contractor Scarsella Brothers Inc. completed a big concrete pour for the roadway at the south end of the northbound SR 99 off-ramp to South Dearborn Street. After the new concrete cures, crews will begin barrier work on that section of the ramp.

Further north on the new ramp, crews are preparing for upcoming barrier pours and doing electrical work for the ramp’s lighting system. Electrical work continues up on the SR 99 on- and off-ramps at the north tunnel portal. Scarsella continues to stripe lanes and ramps at both portals. They’re continuing to mark lanes at the north and south portals, perform electrical work and prepare for several more concrete pours.

Jan. 24

At the south tunnel portal, today crews started paving the southbound SR 99 off-ramp connection to South Royal Brougham Way. Contractor Scarsella Brothers Inc. expects to complete paving the ramp on Friday. At the south end of the northbound SR 99 off-ramp to South Dearborn Street, crews continue placing rebar in preparation for a roadway concrete pour this weekend. At the north end of the ramp, crews are building barrier.

At the north portal, electrical work continues on the new SR 99 on- and off-ramps, and on southbound SR 99 approaching the tunnel.

Crews are continuing to build barriers and perform electrical work on traffic signals at the north and south portals.

Jan. 23 (rain)

At the south tunnel portal, crews started placing roadway deck rebar at the south end of the new northbound SR 99 off-ramp near the stadiums. At the north end of the ramp, the roadway deck pavement has cured enough to allow iron workers to start assembling barrier rebar. WSDOT and contractor Scarsella Brothers Inc. are closely tracking weather forecasts and striping roads and ramps when and where they can.

At the north tunnel portal, roadway and barrier concrete is in place and curing on SR 99 and connecting ramps. The focus now is on electrical work for those ramp connections.

At the tunnel’s north portal, electrical crews continue to get traffic signals ready on the ramps to SR 99. In the tunnel’s south portal, crews are building roadway barriers and have more concrete pours scheduled later this week. Asphalt paving is also planned for later this week, when drier weather is expected.

Jan. 22 (showers)

Despite the rain, crews continued to make progress on connecting lanes and ramps to the new tunnel. At the south tunnel portal, crews completed a concrete pour at the south end of the new northbound SR 99 off-ramp to South Dearborn Street. Barrier work continued on the northbound SR 99 tunnel on-ramp from South Royal Brougham Way. At the north portal, crews continued installing street lights on the Denny Way on-ramp to northbound SR 99. Dry weather later this week could allow crews to complete striping on the southbound SR 99 lanes approaching the tunnel at the north portal.  Work continues to build roadway connections to the new SR 99 tunnel as well as on- and off-ramps. Yesterday construction crews poured a roadway slab for the northbound off-ramp in the tunnel’s south portal area. They have another concrete pour scheduled for today. In the north portal area, crews are doing electrical work and lane markings if weather allows.

Jan. 21

Today construction crews have quite a bit of work at the tunnel’s south portal. Crews worked on the northbound off-ramp that will take drivers into downtown. This ramp is scheduled to open one to two weeks after the tunnel opens to drivers. Crews are also working on building roadway barriers at the northbound on-ramp from South Royal Brougham Way.

Jan. 20

Good progress at the north and south portals. Current construction activities resemble what we’ve seen for the past week: Barrier construction, lane marking and concrete pours.

Jan. 19

At the tunnel north portal, crews finished forming and placing rebar for the on- and off-ramps to Denny Way and also poured the roadway barrier.

At the tunnel south portal, crews are placing rebar on the northbound off-ramp that will take drivers to the waterfront or into downtown and other southern neighborhoods. Over the next few days they have several planned concrete pours as they build sections of the ramp’s road deck.

Jan. 18

Good progress at the north and south portals, installing barriers, striping lanes and pouring concrete at the ramps that will connect the existing highway to the new tunnel.

Jan. 17

Crews poured a stretch of concrete at the tunnel’s north end that will form part of the two southbound SR 99 lanes heading into the tunnel. Crews covered the concrete to protect it from rain, and now it sits to cure.

Jan. 16

Crews building the tunnel connections continue to benefit from the good weather. They’re building barriers on the northbound on-ramp from South Royal Brougham Way into the tunnel, and continuing work on the new intersection at First Avenue South and South Dearborn Street. At the north portal, crews are placing rebar in preparation for concrete pours that are scheduled to occur early next week.

Jan. 15

Crews building connections to the new tunnel continue to make good progress. They expect to finish removing geo-foam from the new South Royal Brougham Way northbound on-ramp later today. Following that, they’ll focus their efforts on installing highway barriers. Several concrete pours will occur in the coming days at both the north and south portals. Striping is also underway on new sections of roadway. Overall, work is proceeding as planned.

Jan. 14

Over the weekend crews completed all scheduled work, which included removing one small section of the ramp that used to carry northbound SR 99 up onto the Alaskan Way Viaduct near the new tunnel’s south portal. Crews are scheduled to begin paving the new South Dearborn Street later this week. Crews are hard at work on the ramps at both ends of the tunnel.

Jan. 13

In addition to highway construction at each of the tunnel portals, crews spent the weekend demolishing a small portion of the viaduct near the stadiums.

Jan. 12

Crews are making quick work demolishing a small portion of the viaduct near the stadiums. Until yesterday, this section of roadway carried northbound SR 99 from the construction detour up onto the viaduct. Removing this section of the northbound ramp makes way for construction of the new intersection at South Dearborn Street, at the new tunnel’s south portal.


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A full timeline of the SR 99 tunnel work since Viadoom began