Motivated by lower cost per ton-mile, U.S. Class I railroads have been replacing 263,000-pound GVW (gross vehicle weight) covered hopper cars (primarily used to haul grain) capable of handling 100 tons with 286,000-pound GVW cars that can handle 111 tons. Since the quality of track on shortline railroads is generally less than that of Class I railroads, it is likely that increasing use of heavy axle load (HAL) cars will have a greater impact on shortlines. If light density rail lines are not upgraded to handle HAL cars, the percentage of the grain car fleet that can move on shortlines will decline, possibly threatening the long-term viability of these railroads. If shortline railroads are abandoned it could have negative consequences for U.S. rural communities. The objectives are to document the shift from 263,000-pound rail cars to 286,000-pound cars by Class I railroads, and to measure the number of route miles and bridges that will require upgrading to handle the HAL rail cars (for a sample of Kansas shortlines). Other objectives include estimation of which branchlines are likely to be upgraded and which will likely be abandoned based on rate of return on investment analysis. The study also measured the road damage cost to state highways if upgrading to handle HAL cars does not occur and shortlines (or parts of shortlines) are abandoned. Analysis revealed that the total cost to upgrade 1,583 miles of mainline track and 1,352 bridges of five Kansas shortline railroads was estimated to be $308.7 million. None of the shortlines in the analysis can earn an adequate rate of return on upgrading track and bridge investment : given their current traffic densities and other characteristics. If the shortline railroads in the study are abandoned, the annual road damage costs in Kansas will increase by over $58 million.