Union Pacific and Norfolk Southern are hoping a do-over on their paperwork can bring the railroads closer to federal approval for their planned $85 billion merger. The railroads refiled their merger application with the Surface Transportation Board (STB) Thursday in hopes of pushing forward with the process. The board, which regulates U.S. railroad freight, denied the first application from the railroads in January. The revised filing quantifies expected market gains, including roughly 303,000 intermodal containers shifting from rival railroads and 2.1 million truckloads projected to convert to rail annually. At the request of the STB, the updated analysis now relies on full traffic data from all six North American Class I railroads, rather than the four that were included in the original application. Union Pacific argued shifting freight from higher-cost trucks to lower-cost rail will save shippers $3.5 billion annually, according to the updated estimate.…