<Li> The Lærdal Tunnel in Norway from Lærdal to Aurland is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 mi). </Li> <Li> The Zhongnanshan Tunnel in People's Republic of China opened in January 2007 is the world's second longest highway tunnel and the longest mountain road tunnel in Asia, at 18 km (11 mi). </Li> <Li> The longest canal tunnel is the Rove Tunnel in France, over 7.12 km (4.42 mi) long . </Li> <Ul> <Li> Williamson's tunnels in Liverpool, from 1804 and completed around 1840 by a wealthy eccentric, are probably the largest underground folly in the world . The tunnels were built with no functional purpose . </Li> <Li> Moffat Tunnel, opened in 1928 in Colorado, straddles the Continental Divide . The tunnel is 10.0 km (6.2 mi) long and at 2,816 m (9,239 ft) above sea level is the highest active railroad tunnel in the US (the Tennessee Pass Line, currently inactive, and Alpine Tunnel are higher). </Li> <Li> The Pennsylvania Turnpike opened in 1940 with seven tunnels, most of which were bored as part of the stillborn South Pennsylvania Railroad and giving the highway the nickname "Tunnel Highway". Four of the tunnels (Allegheny Mountain, Tuscarora Mountain, Kittatinny Mountain, and Blue Mountain) remain in active use, while the other three (Laurel Hill, Rays Hill, and Sideling Hill) were bypassed in the 1960s; the latter two tunnels are on a bypassed section of the Turnpike now commonly known as the Abandoned Pennsylvania Turnpike . </Li> <Li> The Fredhälls road tunnel was opened in 1966, in Stockholm, Sweden, and the New Elbe road tunnel opened in 1975 in Hamburg, Germany . Both tunnels handle around 150,000 vehicles a day, making them two of the most trafficked tunnels in the world . </Li> <Li> The Honningsvåg Tunnel (4.443 km (2.76 mi) long) opened in 1999 on European route E69 in Norway as the world's northernmost road tunnel, except for mines (which exist on Svalbard). </Li> <Li> The Central Artery road tunnel in Boston, Massachusetts, is a part of the larger Big Dig completed around 2007, and carries approximately 200,000 vehicles / day under the city along Interstate 93, US Route 1, and Massachusetts Route 3, which share a concurrency through the tunnels . The Big Dig replaced Boston's old badly deteriorated I - 93 elevated highway . </Li> <Li> The Stormwater Management And Road Tunnel or SMART Tunnel, is a combined storm drainage and road structure opened in 2007 in Kuala Lumpur, Malaysia . The 9.7 km (6.0 mi) tunnel is the longest stormwater drainage tunnel in South East Asia and second longest in Asia . The facility can be operated as a simultaneous traffic and stormwater passage, or dedicated exclusively to stormwater when necessary . </Li> <Li> The Eiksund Tunnel on national road Rv 653 in Norway is the world's deepest subsea road tunnel, measuring 7.776 km (4.832 mi) long, with deepest point at − 287 m (− 942 ft) below the sea level, opened in February 2008 . </Li> <Li> Gerrards Cross railway tunnel, in England, opened in 2010, is notable in that it was built in a railway cutting, that was first opened around 1906 . This arguably is the longest ever tunnel in construction taking 104 years . The tunnel was built using the cut - and - cover method with prefabricated forms in order to keep the busy railway operating . A branch of the Tesco supermarket chain occupies the space above the railway tunnel with an adjacent railway station . During construction, a portion of the tunnel collapsed when the soil cover was added . The prefabricated forms were covered with a layer of reinforced concrete after the collapse . </Li> <Li> The Fenghuoshan tunnel, completed in 2005 on the Qinghai - Tibet railway is the world's highest railway tunnel, about 4.905 km (3.05 mi) above sea level and 1,338 m (0.831 mi) long . </Li> <Li> The La Linea Tunnel in Colombia, 2016, is the longest, 8.58 km (5.33 mi), mountain tunnel in South America . It crosses beneath a mountain at 2,500 m (8,202.1 ft) above sea level with six traffic lanes, and it has a parallel emergency tunnel . The tunnel is subject to serious groundwater pressure . The tunnel will link Bogotá and its urban area with the coffee - growing region, and with the main port on the Colombian Pacific coast . </Li> <Li> The Chicago Deep Tunnel Project is a network of 175 km (109 mi) of drainage tunnels designed to reduce flooding in the Chicago area . Started in the mid-1970s, the project is due to be completed in 2019 . </Li> <Li> New York City Water Tunnel No. 3, started in 1970, has an expected completion date of 2020, and will measure more than 97 km long (60 mi). </Li> </Ul>

What is the central idea of the light at the end of the publishing tunnel