Pursuant to a congressional request, GAO reviewed the advantages and disadvantages of right-of-way alternatives for magnetic levitation (maglev) systems. GAO found that: (1) maglev systems are high-speed ground transportation systems that could relieve highway and aviation congestion, conserve energy, and reduce air pollution; (2) the five basic rights-of-way options that may be suitable for maglev systems include existing interstate and other highway rights-of-way, existing railroad rights-of-way, existing utility rights-of-way, and new rights-of-way through public and private lands; (3) whether any particular option will prove advantageous will depend on local conditions; (4) although existing interstates have adequate space to accommodate maglev systems, GAO can not calculate the cost of collocating with those highways, since it would have to calculate the costs of gaining access to the right-of-way, conforming the guideway to the highway, and acquiring new land in areas where collocations were impractical; (5) each reviewed maglev system project would have to use more than one right-of-way option and acquire new land; and (6) although rights-of-way requirements for each project will differ, sharing right-of-way options, acquisition, and information with system planners could expedite maglev system development, minimize duplication of planners' efforts, and facilitate development of other high-speed ground transportation systems.