At Confusion Hill, similar economic report finally led to construction of a bypass
Caltrans has started an "economic impact study" for Last Chance Grade that will determine how much money it would cost industry and passenger vehicles if there was a complete failure and extended road closure of U.S. Highway 101 at the landslide area south of Crescent City.
And if you don't think that's important, just look 150 miles south.
Before a bypass was completed in 2009, the Confusion Hill landslide on U.S. Highway 101 north of Leggett was so active that at times Caltrans stationed spotters there 24/7. Even when the spotters were off duty, floodlights blanketed the upland portions of the slippery hillside to give drivers more time to avoid a landslide.
Despite the well-documented instability of the Confusion Hill area and several complete road closures due to slides, decades went by before the two-bridged bypass was completed. An economic impact study tipped the scale in Caltrans' decision making.
"I don't think the decision would have been made without it.We had to show them that there was a significant amount of economic impact," said Talitha Hodgson, who was Caltrans' project engineer for the Confusion Hill realignment project.
Now Hodgson, as project manager, is leading Caltrans' efforts to address the similarly troublesome landslide at Last Chance Grade.
The Confusion Hill study found that a full closure of Highway 101 at that location costs the trucking industry and passenger vehicles an extra estimated $228,000 per day.Delays caused by one-lane closures cost the traveling public $56,000 per day.
An estimated 25 percent loss in tourism revenue that would accompany the highway closure would cost Humboldt and Mendocino counties $13 million per month, the 2003 study found.
A full highway closure at Confusion Hill was estimated to create an extra 75 miles of travel for traffic from the Bay Area to the North Coast, similar to what would occur with a slide at Last Chance Grade.
The connectivity of Del Norte County, however, would be even more severely impacted, with a 22-mile trip from Crescent City to Klamath turning into a 300-mile roundabout through Southern Oregon.
Those who commute to or from Klamath for work, school, medical services, police response and anything else, would have to dramatically change their lives until Highway 101 reopened.
"There are impacts that you can't put a dollar on like community connectivity," Hodgson said.
The Last Chance Grade economic impact study is being performed by the Caltrans Division of Transportation Planning, Economic Analysis Branch and is expected to be completed by December 2014.
Caltrans is also completing an Engineered Feasibility Study for Last Chance to be completed by July 2015 that is studying alternatives to the slide-prone section of highway.
For more information, search "Last Chance" at Triplicate.com.
Reach Adam Spencer at firstname.lastname@example.org.