Many railroads are making significant investments in maintenance-of-way projects, with major bridge projects landing near the top of their lists of priorities. Recently, I interviewed bridge experts at several railroads to get a flavor of the kinds of projects under way in 2012. I found out that the bridge work at some roads is necessary to maintain states of good repair; at others, it's to replace worn-out bridges so that new ones can accommodate heavier loads and faster trains. Still other major bridges are being built for special circumstances: One example is the Alaska Railroad Corp.'s Tanana River bridge, which eventually will help to improve U.S. military access to training facilities in Alaska.There are other examples, as well. To read more about them, here's the link to my story in the November issue of Progressive Railroading.