After several years of false starts, it seems the trucking capacity crunch is finally arriving.

The latest evidence came today from consultancy FTR, whose monthly index of trucking conditions showed “unprecedented capacity constraints” in February, similar to the month before. Severe winter weather amplified an already-tight supply situation, and FTR expects a sellers’ market for truckload services to persist for the rest of 2014.

When taking the bad February weather into account, the monthly reading represented the “tightest truck market on record,” FTR said.

Jonathan Starks, FTR’s director of transportation analysis, said the imbalance is driven largely by changes in the regulatory landscape that have compressed driver and rig supply. However, he added in an email that “demand has held up pretty well so far this year.”

In a statement accompanying the results, Starks said shippers and carriers “have to be on the lookout for a potential tipping point when freight demand is able to keep [up] the current high level of truck use well into the summer months.” If that scenario unfolds, shippers will be forced to bid up rates to ensure they have adequate capacity during the fall shipping season, Starks said.