Maglev train

Central Japan Railway Co.'s Maglev train, which is levitated and propelled forward by magnetic force, speeds at an 18.4 kilometer test track in Tsuru, west of Tokyo. (Reuters / June 15, 2004)

A proposal to run a maglev train in the Northeast comes with a hefty price tag — approximately $10 billion just for the segment between Baltimore and Washington. Though the technology holds the promise of transporting passengers from one city to the next in 15 minutes, promoters will have to overcome the legacy of other promising projects that busted their budgets or turned out different than they looked on the drawing board.

Big Dig

By the early 1990s, traffic in Boston's Central Artery, an elevated six-lane highway that ran through the city's downtown, left traffic crawling for more than 10 hours a day. The Massachusetts Turnpike Authority started construction in 1991 to replace the Central Artery with an underground eight- to-10-lane expressway to combat the congestion. The tunnel was not completed until 2007, after the effort had caused major traffic jams, tunnel leaks and the death of a motorist when a 12-ton ceiling panel fell and crushed her vehicle. The cost also swelled from $2.6 billion to an astonishing $24.3 billion, making it the country's costliest highway project.

Baltimore Central Light Rail

The early years were promising when the Light Rail opened in the spring of 1992. By the end of 1993, the $446.3 million service was seeing about 18,600 riders each weekday — more than three times the number of expected. State officials declared that the light rail was more than halfway to its goal of 33,100 riders by 2010. The most recent figures from the Maryland Transit Authority show that the service averaged only 27,253 riders in 2012, and the light rail has also faced criticism about crime and limited parking at its stops.

Alaskan Way Viaduct

The Alaskan Way Viaduct, a highly trafficked elevated roadway that runs along a waterfront in downtown Seattle, was severely damaged following a 2001 earthquake. After a politically contentious decade-long debate, the decision was made to replace the roadway with a tunnel that would run two miles. Alternate proposals included creating another elevated roadway or doing away with the viaduct and improving public transportation options. The major drawback to the tunnel? Construction, which began this summer, is expected to cost more than $3 billion.