An employee helps install a traction motor onto the truck of a General Electric Evolution Series Tier 4 diesel locomotive at the GE Manufacturing Solutions facility in Fort Worth, Texas.

Business economists expect the U.S. economy to pick up speed next year, but not as quickly as Donald Trump promised during the election campaign.

In their latest economic outlook, forecasters surveyed by the National Association for Business Economics said they expect the U.S. gross domestic product to end 2016 with an average annual growth rate of just 1.6 percent, before strengthening next year to a 2.2 percent annual growth rate.