LOUISVILLE, Ky. — The 40th Mid-America Trucking Show here grew by more than 7% from 2010 in terms of visitors and exhibitors, but fell short of establishing new records in either category.

Class 8 truck manufacturers have a backlog of nearly 100,000 units scheduled to be built over the next 12 months, more than double the number of a year ago, because of a substantial increase in orders over the winter, ACT Research Co. reported.

LAS VEGAS — The dynamic heavy-duty truck market is becoming more closely connected globally, with manufacturers of parts, components and whole vehicles competing fiercely worldwide while more national governments impose significant regulations on carbon dioxide emissions, industry executives said.

Truck manufacturers said they are prepared to boost production to meet increasing demand in 2011, although some experts warned shortages of key components could develop as suppliers struggle to keep up with what could be one of the strongest sales markets in years.

Three truck manufacturers and engine maker Cummins Inc. all reported improved revenue in the third quarter as the market for new trucks in North America continued to improve.

The Heavy Duty Manufacturers Association said 84% of its members experienced sales growth during the second quarter, with 28% reporting “substantial growth.”