Like the spring weather, national average truckload rates on the spot market are in a seasonal warming trend after weeks of mixed results.

Outbound rate averages in the West, South Central, and Southeast regions heated up for all types of truckload freight, and freight availability increased nationwide for the week ended May 4. The national average van rate on the spot market increased to $1.81 per mile (all rates include fuel surcharge), up 0.6% week-over-week. Reefer rates jumped 3.1% to $2.12 per mile. The flatbed trend also held, increasing 1.8% to $2.19 per mile. To the numbers:

Van Freight

Trending Up: Rates increased the most in Philadelphia (up 3.7% over the week), Memphis (3.2%), Stockton (2.4%), and Buffalo (2.3%). Six of the top 13 van markets showed positive rate trends over the last four weeks.

On individual lanes, Memphis to Columbus gained 31 cents (16.3%) to $2.21 per mile; Charlotte to Philadelphia was up 24 cents (9.9%) to $2.67 per mile; and Columbus to Memphis jumped 18 cents (11.7%) to $1.72 per mile.

Trending Down: Seattle rates lost 3.6%, the largest rate decline among top markets last week. Denver saw the largest dip in freight availability among top markets, accompanied by a 2.7% decrease in outbound rates. Seven of the top 13 van markets are trending down over the last four weeks.

Best Van Lane: Chicago to Buffalo was up 16 cents to $2.74 last week, a total 39-cent increase over two weeks.

Reefer Freight

Trending Up: Rates increased the most in Lakeland and Miami, up 16.5% and 15.3% respectively over the week. Ten other markets saw rates increase as we move into the harvest season, including Salt Lake City (up 8.8%), Phoenix (5.9%), and Green Bay (5.3%).

On individual lanes, Lakeland to Charlotte gained 63 cents (44%) to $2.06 per mile; Miami to Elizabeth increased 45 cents (21%) to $2.55 per mile; and Green Bay to Philadelphia jumped 40 cents (15.7%) to $2.94 per mile on increased dairy shipments.

Trending Down: Ontario, Calif., rates dropped 3.5% last week, the largest decrease among top markets. Five of the top 14 reefer markets are down over the last four weeks, likely due to late winter weather.

Best Reefer Lane: Green Bay to Philadelphia paid $2.94 per mile last week.

Flatbed Freight

Trending Up: Rates increased the most in Houston, up 6.9% over the week. Rates in 13 of the top 20 flatbed markets trended up over the past month. On individual lanes, Roanoke to Harrisburg gained 40 cents (15.4%) to $2.99 per mile; Houston to Fort Worth is up 26 cents (11.2%) to $2.58 per mile; Cleveland to Chicago jumped 24 cents (10.8%) to $2.47 per mile.

Trending Down: Pittsburgh rates dropped 5.3% last week, the largest decrease among top markets. Raleigh rates dropped 4.7%, as demand dipped in the market, while Harrisburg lost 4.2%.

Best Flatbed Lane: Baltimore to Springfield, Ill., paid $3.99 per mile last week.

Source: DAT® RateView (formerly the Truckload Rate Index) and DAT Network of load boards, which facilitates the matching of more than 60 million spot (non-contract) loads and trucks per year. Rates are national averages derived from the DAT Truckload Rate Index.