The Iowa Department of Transportation is partnering with two railroads to upgrade what it says is a key 78-mile stretch of track in eastern Iowa. D-O-T spokesman Jan Wiley says it’s a four-point-two million dollar project.The track extends from Homestead near the Amanas, east to the state line. The work will upgrade the track to handle new heavy-axle grain cars. Wiley says the new cars are becoming the standard for hauling grain.The old cars haul 263-thousand pounds, while the new rail cars handle 286-thousand pounds. The D-O-T is loaning 50-percent of the cost of the project to the railroads. The Burlington Northern and Sante Fe Railroad and the Iowa Interstate Railroad are paying the rest of the cost. The D-O-T loan comes from a special fund set up for just such projects. The work will start this summer, and Wiley says it will probably be finished next year.