The Transportation Intermediaries Association has published a document to its members citing IRS publications that note the following:
Payments to companies for the transportation of freight are exempt from 1099 reporting
Section 1.6041-3(d) of the Income Tax Regulations excepts freight payments from
information reporting. Section 6041A was added to the law by § 312(a) of the Tax
Equity and Fiscal Responsibility Act of 1982, 1982-2 C.B. 561.
Read more directly from the IRS below
• 1999 IRS Chief Counsel Memorandum
• 2014 IRS Chief Counsel Memorandum