Should shortline railroads upgrade their systems to handle heavy axle load cars?

Motivated by lower costs per ton-mile, US Class I railroads have been replacing 263,000-pound gross vehicle weight (GVW) covered hopper cars with 286,000-pound GVW cars. In many cases, shortline railroads would have to upgrade their tracks and bridges to handle the heavier cars. This paper used rate of return on investment analysis for a sample of US shortlines to determine if shortline owners will likely upgrade their infrastructure or abandon the railroad. Analysis revealed that the total cost to upgrade 1583 miles of mainline track and 1352 bridges of five shortline railroads in one US Midwest state 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. If the shortline railroads in the study are abandoned, the annual road damage costs will increase by over $58 million.