Industrial production, which tends to closely correlate with changes in demand for trucks and trailers, advanced 1.1% in May after having risen 0.8 % in April, according to the Federal Reserve.
At 116.9% of its 1997 average, output was 6.3% higher than its level in May 2003.
Manufacturing output increased 0.9% in May and was just 0.3% below the peak reached in June 2000. Output at utilities increased 3.3%, a gain reflecting unseasonably warm weather, while production at mines edged down 0.4%.
Capacity utilization for total industry increased to 77.8%, a rate that is 3.7% percentage points above its value in May 2003 but still 3.3 percentage points below its 1972-2003 average.