Six Southeastern states are joining to push for an alternative to busy freeways — an ambitious, high-speed train network that would connect the southeast and link it with Washington, D.C., Alabama, Georgia, North Carolina, South Carolina, Virginia and Tennessee. Proponents in Congress recently won $750,000 in federal funds to study the possibility of such a system. Business leaders in the region, who are spearheading the effort, are lauding the rail proposal's financing scheme. The federal government would pay for building the rail network at an estimated $6 billion, but once the tracks were completed, a private business would operate it, using its own rail cars and without government subsidies.