Intermodal rail traffic levels remained strong in August, hitting new highs or coming close to it, according to the Association of American Railroads.

U.S. railroads originated 1.08 million containers and trailers during the month, up 4.3% or 44,520 carloads, compared with the same time a year ago. The weekly average of 268,922 intermodal units in August was the second highest on record, slightly behind the June 2014 record.

Overall U.S. rail traffic for August also saw both carload and intermodal volume increasing compared with August 2013. U.S. railroads originated 1.2 million carloads last month, up 2.9% or 33,838 carloads compared with August 2013. Total carloads averaged 303,072 per week in August, which is the highest weekly average for any month since October 2011 and the highest for August since 2008.

The group also reported increased rail traffic for the week ending August 30. U.S. railroads saw intermodal volume for the week totaling 273,458 units, up 5.3% compared with the same week last year and the highest for any week in history. Total U.S. rail traffic for the week was 579,209 carloads and intermodal units, up 3.1% compared with the same week last year.

In August, combined U.S. railroad carload and intermodal volume was 2.29 million units, up 3.5%, or 78,358 units compared with August 2013. Average weekly volume was 571,994 carloads, containers, and trailers.

AAR also reported U.S. Class I railroads originated 119,634 carloads of crude oil in the second quarter of 2014, 8.6% more than the first quarter of 2014 and the most ever in any quarter. In the first half of 2014, crude oil accounted for 1.6% of total originated carloads for U.S. Class I railroads.

For the first 35 weeks of 2014, U.S. railroads reported cumulative volume of 10.13 million carloads, up 3.6% from the same point last year, and 9 million intermodal units, up 5.7% from last year. Total U.S. traffic for the first 35 weeks of 2014 was 19.14 million carloads and intermodal units, up 4.6% from last year.