The federal government has ordered a possibly years-long review of proposed changes to the Ohio River Bridges Project.Last month, Mayor Greg Fischer, Kentucky Governor Steve Beshear and Indiana Governor Mitch Daniels proposed cutting lanes from the east end bridge, dropping pedestrian paths from the downtown bridge and rebuilding Spaghetti Junction in place. The cuts, they say, would shave about $500 million off of the projects' $4.1 billion cost.As the Courier-Journal reports, the changes will require new environmental research. In other states, similar federal reevaluations have taken years to complete, but an official with the Ohio River Bridges Project told WFPL's Rick Howlett the new studies should only take one year.A conference on how best to complete the project will be held in Louisville on Wednesday and Thursday.