VANCOUVER, Wash. — Building a multi-billion dollar bridge to replace the Interstate Bridge is an enormous project that starts with a great deal of planning and efforts to get people on board.
We've already seen some 3D design drawings that show a few possibilities of what may be to come for the I-5 Columbia River crossing. But at a Thursday meeting of top players from both sides of the river, we got the most realistic look yet at possible bridge designs, from several angles.
There are six designs in all, including single level, double deck (or stacked) — and yes, a lift-span version too.
Interstate Bridge Replacement Program Administrator Greg Johnson said they are well past the first step in a long process, but these designs are not set in stone.
"Not final design, but this is showing possible bridge configurations and bridge types so that folks can start thinking about the tradeoffs with different configurations,” said Johnson.
So what types of bridges are these? The single deck bridges vary, from one that will remind you of the Glen Jackson bridge on I-205 to two others with decks held up by cables; one where the cables are exposed and another "finback" version, where the cables are encased in concrete housings. Both are low profile to accommodate air traffic.
And then there is the version most partners connected to the IBR program want to avoid: a lift-span version, to accommodate a U.S. Coast Guard request, designed just in case ship clearance requirements can't be worked out.
“And finally, the two-level configuration. It saves on width and overall impact, but it also has trade-offs for people's experiences if they're walking, riding bikes or on light rail,” said Johnson.
That's because those users would be on the somewhat enclosed lower deck of that bridge design.
Choosing a bridge type is not likely tp happen until February of next year. For now, these models are out for the public's viewing and opinions. As for the program administrator, he's not about to tip the scale.
“I like them all, I think all of them have a lot of positive attributes,” said Johnson. "If any one of those are chosen, I think the area will be proud of what is built over the Columbia River."
The IBR Program has the visualization renderings online, and also a calendar of upcoming community meetings, including a Vancouver Neighborhood Forum on May 31 and a Portland Neighborhood Forum on June 6.