DOT planning beefier bridge, road for trucks
The Alaska Department of Transportation is designing the Chilkat River Bridge to the highest industrial standard in anticipation of possible large shipments, Haines Borough Manager Mark Earnest said during last week’s planning commission meeting.
Chuck Correa, regional pre-construction engineer for DOT, confirmed the bridge will likely be designed to handle heavier loads, but clarified the final decision is pending a smooth federal environmental process.
“I don’t see anything on the horizon that’s really going to jam this project up,” Correa said.
The heavy industrial design will be able to hold trucks up to 195 feet in length and 200,000 pounds in weight. Earnest said the enhanced bridge will allow the Haines Highway to act as a corridor for major shipments of minerals, gas, or heavy machinery traveling to and from the Yukon and Alaska’s interior.
Mining firms have not yet committed to using the road for heavy loads.
“We don’t want to give the impression that there are ore trucks ready to come barreling down the highway next month, because that’s not the case. These are projects that are potentially many years out; they are speculative,” Earnest said.
Correa said the bridge would cost $12 million under a standard design and would see a less than 10 percent bump in cost to bear heavier loads. Much of the extra expense would be due to heavier, more expensive girders, typically ineligible for federal funding. Correa said exceptions have been made, however, and the state might be able to secure federal funds for the cost difference.
Earnest said an additional 1.5-inch overlay of asphalt would need to be added to the entire road – from the border to town – to accommodate heavy industrial traffic, but Correa said it is too soon to tell.
“There definitely would be more asphalt thickness needed, but until we know the truck size and the number of trucks that would be traveling the road, I wouldn’t be able to tell you if it was one inch or two inches or three inches,” Correa said.
In relation to the $100 million price tag for building the bridge and widening the road between 25 Mile and 3 Mile, extra asphalt is relatively inexpensive, Earnest said. Correa, however, said the extra asphalt would cost “tens of millions of dollars.”
“Again, it really depends on whether you’re putting down an inch-and-a-half or two or three. That can’t be determined until a haul is imminent and we know what kind of loading and number of trucks would be used on the road,” Correa said.
In addition to bringing the bridge up to heavy industrial standards, the project will include six-foot shoulders on both lanes for bicycle safety, and address other safety issues including alignment, grades, curve radii, and debris flow problems. Aside from two 45 mile-per-hour curves, the highway will be a 55 mile-per-hour speed zone.
Construction on Mile 21 to 25.3 and the bridge should begin in the next year or two and is expected to cost $33.5 million, Correa said. Funding already has been secured for that phase.
Federal sources account for 90 percent of the project’s funding, with a 10 percent match by the state.
Correa said the project will be publicly advertised for comments in February or March. After the 30-day public comment period, the Federal Highway Administration will review the environmental document and comments.
A resolution supporting the heavier bridge design will come before the assembly during its Nov. 27 meeting.