Freight demand in the trucking industry remains weak following an unusually slow fourth quarter last year, and higher fuel and equipment costs are putting added pressures on companies’ revenues, the Associated Press reported.

Diesel fuel prices rose 5 cents from the previous week to $2.84 per gallon as of April 9. In addition to higher fuel costs, equipment costs are also rising as a result of new emissions regulations that went into effect this year. Trucks with engines that burn ultra-low-sulfur diesel cost $15,000 more than previous models. Maintenance costs on the new engines are also higher.

A driver shortage also continues to affect the trucking industry, causing companies to pay more for qualified drivers. Based on current trends, the American Trucking Association says the shortage of drivers could reach 111,000 by 2014.

Paul Bingham, an economist at Global Insight Inc., a Waltham, Mass.-based consulting company, blames the housing downturn and production cuts by automakers for some of the trucking industry’s problems. But he sees improving conditions on the horizon.

“You’ve got headwinds blowing across the board,” Bingham said. “The good news is that by the end of the year these pressures won’t be so great.”