Reading4加拿大落矶山脉国家公园内环境冲击极小化之公路改善策略.DOC

Strategic Highway Improvements to Minimize Environmental Impacts within the Canadian Rocky Mountain National Parks 加拿大落磯山脈國家公園內環境衝擊極小化之公路改善策略 Highway twinning 公路拓寬 Project description 計畫描述 The need for twinning is based on maintaining an acceptable level of service and highway safety. The passing lane system on the TCH helped extend the design life of the highway as a two-lane facility by approximately 15 years. However, steadily increasing commercial, private, and tourist traffic has ultimately led to the need to commence twinning the TCH in Banff National Park in phases over the past decade (Parks Canada 1995). The latest 18.6-km stretch between Sunshine and Castle Mountain Interchanges, and known as Phase IIIA, was completed in 1998. 公路拓寬的需求是基於要維持一個可接受的服務水準及公路安全。加拿大橫貫公路(Trans-Canada Highway, TCH)上設計的超車道系統，讓兩線道公路設計的使用年限延長了大約15年。然而，持續增加的商用、私人及觀光的車潮，最終使得班夫國家公園內的TCH道路在過去十年必須分期進行拓寬工程。必威体育精装版的18.6公里是綿延在陽光山(Sunshine Mountain)交流道及城堡山(Castle Mountain)交流道之間─被稱為第3A期工程，於1998年完工。 This section of the TCH prior to twinning comprised two lanes with passing lanes added in the early 1980s using existing shoulders to enhance the level of service as part of the strategy to extend the design life of the TCH. Accident rates were higher than the average Canadian two-lane highway and double that on the adjacent four-lane divided section. A level of service (LOS) analysis determined that for 2000 h of the year the highway was operating at LOS D and E which affected 1.6 million vehicles or 54% of the yearly volume of 3 million vehicles. Thus, this section of the TCH was operating well below the design LOS C. During summer months, daily volumes between 18 000 and 20 000 vehicles per day were recorded on a regular basis. In addition, this section had a high wildlife collision mortality, affecting the safety of the driving population as well as the animal population (Parks Canada 1995). TCH這部分的路斷在拓寬工程之前為雙車道，在1980年代初期，利用現存的路肩加設了超車道，以提高服務水準，這是用來延長TCH設計的使用年限之一種策略。其肇事率高於加拿大兩線道公路的平均且是鄰近四線