Despite a surge in e-commerce freight, the DAT Freight Index indicates that truckload freight volumes slipped 27% in December 2018 compared to the same period the year before.

Load availability on the spot market has been trending downward since August 2018, as capacity loosened and trucks became more available. Even with the downturn in volume, it was still up 7% overall in 2018.

Flatbed rates remained stable compared to November 2018, but rates fell slightly for dry van and refrigerated segments due to declining fuel surcharges.

Rising e-commerce freight failed to bolster spot market numbers in 2018 because retailers and contract carriers appeared better prepared to handle the rush, according to DAT market analyst Peggy Dorf.

"Contract carriers handled a bigger share of the seasonal loads, taking advantage of new equipment and improved driver retention," said Dorf.