The key to this question is does the shipper have customers that can handle railcar volumes? Does their customer have rail service or a nearby transload that can unload the commodity and deliver by truck?
For example, a shipper of canned goods in Wisconsin is shipping trucks to California. I helped them ship trucks to a transload in Chicago, load in a boxcar, rail to California transload, and truck to the final destination.
I once was approached by 3 different roofers buying sheathing in truckload quantities. I put them together so they bought a boxcar of sheathing from the mill, shipped to a transload, and divided into 3 groups and picked it up as they needed it saving them $500 per truck.
I have loaded lumber from sawmills without rail service by trucking to a transload and moving by rail to the final destination.
Again rail rates, volumes, final destinations, and storage, are all factors leading to reduced transportation charges. If this seems a bit daunting, please feel free to contact me at mekershaw@comcast.net and we will use Commtrex to locate transloads that can help you with your transportation needs.