Item: I-90 Snoqualmie Pass: Review of Highway Operations During a Major Construction Project in an Active Avalanche Area
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Title: I-90 Snoqualmie Pass: Review of Highway Operations During a Major Construction Project in an Active Avalanche Area
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- John Stimberis [ WSDOT, SEATTLE, WA, USA ]
Date: 2016-10-02
Abstract: Interstate 90 over Snoqualmie Pass, WA is affected by numerous avalanche paths that disrupt travel and threaten the safety of travelers. The most active paths affecting Interstate 90 had a snow shed to protect travelers, but highway expansion in the 1960's added two lanes alongside the snow shed exposing eastbound vehicles to avalanches, leaving only the westbound lanes protected. An avalanche forecasting and control program has been in place since the early 1970's to further protect travelers. Up to 40 avalanche control missions may occur at the snow shed site each winter. Increasing traffic volumes and commerce have made traffic delays less acceptable as avalanche delays and closures have an economic impact that often exceeds several million (USD), depending on the length of the closures. The existing snow shed is being replaced with two bridges as part of a $550 million (USD) highway expansion project. The snow shed was removed in 2014 to make room for construction activities. The construction season usually runs from May through October and is suspended during the winter due to snowfall and avalanche hazards, thus the most active avalanche area was left without a snow shed for two winters. The author is providing a follow up to I-90 SNOQUALMIE PASS: OPERATING A HIGHWAY AVALANCHE PROGRAM DURING A MAJOR CONSTRUCTION PROJECT (Stimberis 2012), including an overview of how we managed the site during those two winters, which included a record low snowfall winter followed by a record high snowfall for December 2015. In addition, the author looks ahead as the site moves away from avalanche control and we begin to gather data on natural avalanche activity
Object ID: ISSW16_P4.09.pdf
Language of Article: English
Presenter(s):
Keywords: snow shed, avalanche fences, avalanche forecasting, avalanche control, highways
Page Number(s): 1209-1212
Subjects: avalanche forecasting avalanche control highways
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