The change in outlook is based on traffic performance that is significantly lower than anticipated and the prospects for a longer ramp-up period, leading to lower coverage and reduced financial flexibility.

The Southern Connector is a 16-mile, four-lane toll road extending east to west from the intersection of I-85/185 to the intersection of I-385 in southern Greenville. The road was built to serve a growing area. The association is a nonprofit formed in 1996 to construct and operate the toll road.

The rating reflects substantially lighter traffic than was expected based on the 1997 feasibility study. Recent average daily traffic is 64% less than originally forecasted level for the first year. Traffic has increased since the road opened in March, the company says in a prepared statement.

S&P also cited concern over the road's ability to weather a rocky economy.

"It was expected that the road would encourage development in the region," the bond-rating firm says. "However, the Southern Connector has been affected by slower-than-expected area development and a slowing economy. Some of the issues with development are compounded by the fact that the toll road opened 9-1/2 months ahead of schedule, prior to some of the development activities in the region were forecast to occur. In addition, the national recession has also slowed development in an otherwise strong economic region."