The number of spot market loads on the DAT network of load boards gained 1.2% and truck posts were up 3.6% during the week ending May 12, which had a moderating effect on rates. The spring shipping season may be late, but it's finally here, especially in produce-distribution markets. This helped push the national average reefer rate up 1 cent over the past week to $2.49 per mile.

In contrast, the national average van rate fell 3 cents to $2.15 per mile, while flatbeds declined 7 cents from the previous week to an average of $2.71 per mile.

The small improvement in rates, which include fuel surcharges, happened as the national average cost of fuel increased 2.2% over the previous week to $3.24 per gallon.

• Van: $2.15/mile, down 3 cents week over week

• Flatbed: $2.71/mile, down a penny after a 7-cent increase the previous week

• Reefer: $2.49/mile, up 1 cent

Vans: Overall van load posts increased 7% while truck posts increased 3%. That caused the van load-to-truck ratio to increase 3% to 6.4-to-one. Many key average outbound rates were weaker:

• Columbus, Ohio: $2.48/mile, down 8 cents. Columbus to Buffalo, an important regional van lane, fell 25 cents to an average of $3.70/mile

• Houston: $2.12/mile, down 2 cents

• Memphis: $2.67/mile, down 1 cents

• Los Angeles: $2.45/mile, up 3 cents

Flatbeds: Nationally, the number of flatbed load posts declined 1% while truck posts increased 8%. That caused the load-to-truck ratio to cool, falling 8% to 102 loads per truck.

Reefers: Refrigerated load posts fell 3% while truck posts increased 6%. That caused the national load-to-truck ratio for reefers to decline 8%, from 9.2-to-one to 8.5-to-one loads per truck. The average outbound rate from Miami jumped 25 cents to $3.29/mile, and several lanes showed gains:

• Miami to Baltimore: $3.49/mile, up 24 cents

• Los Angeles to Portland: $3.42/mile, up 15 cents

• Dallas to Houston: $3.03/mile, up 6 cents

• Elizabeth, N.J., to Boston: $4.35/mile, up 11 cents

Related: Spot Truckload Freight Posts Record April Volume, Rates Up Over Last Year