It used to be that railroads would build smaller, simpler intermodal terminals to serve local markets (more) directly than they could through regional hubs. Somerville, for example, had a TOFC ramp into the Conrail era. With some exceptions, though, the trend has overwhelmingly been towards large and highly mechanized metropolitan terminals accessed with drays that often break 100 miles. Something like 90% of intermodal terminals extant in the 1960s have since closed. Concentrating traffic helps defray the capex of new terminal construction while keeping operational complexity down for railroads--both of which are important, because intermodal's cost base lies disproportionately in terminal ops, and structurally speaking intermodal equipment/terminals are not set up for extensive sorting. All of that said, this does have some negative impacts on IM's competitiveness and environmental impact, and there have been some (limited) success stories wherein short lines, e.g. the Indiana Railroad, have set up terminals to extend rail hauls closer to customers.