This post originally appeared on Orphan Road.

The P-I gives us the rundown on the looming construction mess:

The state wants the job done quickly so I-5 is usable when initial work begins next year to replace the Alaskan Way Viaduct. There was no way to keep more lanes open and allow crews to work safely, state officials said, or to spread it over nights and weekends and get the work done before fall rains begin.

Initially, up to two lanes at a time between Spokane Street and I-90 will be closed, then three lanes toward the end of the job during the work — 24 hours a day, seven days a week.

“In terms of the impact to traffic, this is going to be the biggest,” said state transportation spokeswoman Jamie Holter of the $15.5 million project. “There isn’t a place in the state where you have that many vehicles on the road.”

WSDOT is doing everything it can to get the word out, Metro is pitching in with increased bus service. One logical piece would be to reroute through-traffic to I-405. In fact, as I’ve argued before, when they finally widen 405 in 10 or 20 years, they ought to re-name it I-5 and make the route through Seattle — the one that goes down to one northbound lane at Seneca Street — I-405 or I-205, like in Portland.

Who knows, maybe through-traffic isn’t significant enough to make a tangible difference, or maybe even the wider I-405 can’t handle the increased traffic.