UPDATED -- Spot market freight volume continued to achieve record-setting levels in August, increasing 32% compared to the same month in 2013, while freight availability remained constant, with just a 0.4% uptick from July to August, according to the DAT North American Freight Index released Tuesday.

Compared to August 2013, freight volume rose for all three equipment categories in the U.S. Van load availability rose 36%, while refrigerated freight increased 31% and flatbed volume surged 56%. The index reflects spot market freight availability on the DAT Network of load boards in the U.S. and Canada.

U.S. average spot truckload rates, less fuel surcharge, also increased, with van and flatbed rates both adding 14% and reefer rates up 5.7%. Vans averaged $1.80 per mile, flatbeds $1.92 and reefers $1.80. With fuel surcharge the rate was $2.27 for vans, $2.42 for flatbeds and $2.28 for reefers.

Compared to July, freight volume was stable for vans with a 0.2% increase, and freight for reefer trailers increased 6.2%. Loads for flatbeds, however, declined 2.4%, from July's atypically strong demand.

Spot market truckload rates for all three equipment categories receded from extraordinary mid-summer heights. Van rates slid 1.9%, reefer rates lost 2.2%, and flatbed rates drifted 0.5% lower from July to August.

Update adds spot market rates with and without fuel surcharges.