Dot Planners Get The Drop On I-90 Lowering Roadbed, Expanding To Six Lanes Considered
The highway may be sinking, but there’s no cause for alarm.
The Idaho Department of Transportation is considering lowering Interstate 90 where it traverses the Lake City - to deal with a series of overpasses that are too low, either trapping trucks or sending them cross country.
I-90 also may be expanded to three lanes each way to deal with traffic that peaks at 40,000 cars a day between the Northwest Boulevard interchange and the Fourth Street interchange.
“The concept is to rehabilitate the pavement and raise the structures, lower the freeway or a combination of both,” said Larry Wolf, assistant district engineer for North Idaho.
Five overpasses that channel city traffic over the top of the interstate are too low - Northwest Boulevard, U.S. Highway 95, Seventh Street, Ninth Street and Government Way.
The Northwest Boulevard overpass is supposed to be replaced within the next three to four years and will be raised to the preferred 16-1/2 or 17 feet.
It will be at least 2003 before any construction work is done, but preliminary design and development is well under way.
The estimated cost is roughly $9 million.
There is no doubt that the I-90 paving, which has endured 37 years with little major maintenance, will have to be replaced. The key question is whether it makes more sense to raise the bridges or lower the roadway by several feet.
If the bridges are raised, the companion city streets have to be raised, Wolf said. That means dealing with right of way that is private property.
On the other hand, lowering the interstate means revamping the storm drainage system.
City officials just hope for a solution. “The Government Way bridge is hit all of the time,” Mayor Al Hassell said.
Several years ago, a large truck was so jammed under the overpass that several wreckers couldn’t free it. The tires had to be flattened and heavy equipment had to be summoned to break it free, Hassell said.
As it is, westbound trucks get off at the 15th Street exit - the Sherman Avenue interchange bridge is too low for it to be part of a detour and weave through town until they can get past the overpasses. If the trucks are too big for Northwest Boulevard, they end up motoring all of the way to Post Falls before getting back on the interstate.
It’s a pain for truck drivers, and it causes undue wear and tear on city streets, Hassell said.
Increasing the number of lanes also is high on the city’s wish list. “The traffic has increased exponentially on all of the city streets, especially I-90 and Highway 95,” the mayor said.
“My opinion is this would solve the local traffic problems through town.”
Meanwhile, there are indications that the city’s highest priority finally may come to pass. The Transportation Department expects to hold a public hearing this fall announcing the proposal for replacing the Northwest Boulevard overpass.
Traffic backs up for blocks each direction from the too-narrow bridge during rush hour. The odd configuration of interstate on-ramps prompts desperate drivers to take all kinds of unnecessary chances. The curve in the bridge makes visibility difficulty.
“I’ve seen examples in just the last week that would make your hair stand on end,” Hassell said.
The reconstruction was supposed to begin in 1998 but was delayed.
If the Transportation Board concurs, replacement of the 1950s era bridge now will begin in 1999 and will cost about $6.4 million. It will be built in two halves.
The eastern half will be constructed first and all traffic diverted onto it. Then old bridge will be replaced with the western half of the bridge.
The new bridge will be five or six lanes wide and will have a sidewalk. It will include new on-ramps for drivers wanting to travel toward Spokane. And the intersection of Appleway and Ramsey Road will be moved north.
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