雪山隧道內車流特性與容量之分析

Traffic Flow Characteristics and Capacity Analysis in Shea-San Tunnel

張瓊文(Chiung-Wen Chang) ； 林豐博(Feng-Bor Lin) ； 曾平毅(Pin-Yi Tseng) ； 蘇振維(Cheng-Wei Su)

《中國土木水利工程學刊》 22卷3期 (2010/09) Pp. 333-340

https://doi.org/10.6652/JoCICHE.201009_22(3).0009

摘要

國道五號之雪山隧道長達12.9公里，採雙孔單向行車的設計。為了減低事故危害與提高運作效率，原來只允許小車以70 km/h之速限通行；2007年10月起雪山隧道以外路段之速限提高為80 km/h，同年11月開放大客車通行所有隧道，且在2008年3月雪山隧道之速限亦提高至80 km/h，從2007年通車到現在，唯一不變的交通管制是在正常行車狀況下，前後車距離最少須50公尺。雖然交通管制策略數度修改，本文分析隧道內偵測器資料發現，雪山隧道的容量仍然偏低。透過本文之探討，可進一步了解雪山隧道在時間與空間向度上之容量變化情形、自由車流速率、大客車之小客車當量、及流率與速率關係。

關鍵字

自由速率 ； 車流特性 ； 長隧道 ； 容量 ； 交通管制

並列摘要

The 12.9-km long Shea-San Tunnel is located on National Highway 5 (NH-5). It has two one-way tubes. To minimize accidents and to respond to the need for improved operating efficiency on the NH-5, a uniform speed limit of 70 km/h for the NH-5 and allowed only passenger cars and other small vehicles to enter the Shea-San Tunnel was regulated. Except for the Shea-San Tunnel, the speed limit was raised to 80 km/h in October 2007. In November 2007, the tunnel was also opened to commercial buses. And, in March 2008, the speed limit in the Shea-San Tunnel was raised to 80 km/h. One traffic regulation that has not been changed is that the motorists in the Shea-San Tunnel must maintain a minimum car-following distance of 50 m under normal conditions. In spite of the changes in traffic control measures, however, the capacities of the two tubes in the Shea-San Tunnel are still low. This study uses detector data to examine the spatial and temporal variations of capacity, free-flow speed, passenger car equivalent of buses, and speed-flow relationship in the tunnel.

並列關鍵字

capacity ； flow characteristics ； free-flow speed ； long tunnel ； traffic control