Commuters who ride up and down the I-5 corridor watch the bridge grow as they slow down near an interchange under construction at the Ridgefield exit. Begun in 2009 with the help of federal stimulus money, construction on the $23 million interchange is moving briskly and could be finished before the projected late 2011 date. Tapani Underground of Battle Ground is the general contractor for the project. Tapani’s Nathan Kaski, construction supervisor, said the construction part of the project is “about three-quarters complete. We’re ahead of schedule.” Abbi Russell, spokeswoman for Washington State Department of Transportation (WSDOT), hesitates to project too much optimism, saying that weather and other unforeseen events can delay even the best laid plans. One such delay took place early last winter when construction workers found a mammoth tusk under what would become one of the ramps. “That was a big surprise,” Russell said. “It was pretty exciting.” Archeologists examined the area and when “no more pieces came up” construction continued, she said. The tusk was removed for further study. Crews had fairly smooth sailing except for the mammoth tusk, although weather extremes cause problems as materials shrink and expand, occasionally causing delays. “The weather does affect construction,” Russell said. “It impacts how everything works.” Construction crews worked on the new bridge across I-5 on July 13, placing rebar and pouring concrete in a coordinated and meticulous process. Each step in building the multiple layers of the roadbed is important, as the process requires construction materials to season and cure, said WSDOT’s chief inspector Neil Francis, who spends his days working closely with the 25-worker Tapani crew and subcontractors. When the bridge and the ramps are finished, maybe as soon as mid-August, the old bridge will be taken down, Kaski said. Crews will demolish the old bridge in late evening, after the rush hour traffic has passed. Traffic along I-5 will not stop, but will be routed around the ramps and feeder roads, Russell said. “Excavators will chew through the concrete” to bring down the bridge, Kaski said, adding that crews will be paving into September. Traffic through the Ridgefield interchange has grown with the development of an industrial area east of I-5. State and city officials have planned for a new interchange since the early part of the new century. Safety at the interchange was addressed in 2004-05, when WSDOT added full traffic signals at the end of the north and southbound ramps. Replacing the stop signs has been a “stop-gap” measure, Russell said. “This project was in the 20-year plan,” she said. “We had completed 90 percent of the design, but we did not have enough funds–about $2 million short–to finish. We shelved the project in 2008.” The stimulus package provided $8.2 million, which added to $2.9 million in pre-existing funds and $11.96 million from the gas tax, she said. Construction of the interchange and bridge is the first stage of a two-stage process. The second stage, largely a City of Ridgefield project, will include building roundabouts at SR 501 and 65th Avenue and at SR 501 and South 56th Place. Twelve-foot wide sidewalks will be added to connect to the sidewalks that will cross the new bridge. The second stage will be funded with a $5.3 million grant from WSDOT. Bids will be let in April 2011, under the plan, Russell said.