DENVER - E-470, the high-speed toll road around metropolitan Denver's eastern perimeter, recorded its fourth straight year of traffic growth, according to 2013 year-end figures released Thursday.

The E-470 Public Highway Authority released unaudited figures showing that traffic, as measured by the number of toll transactions, increased 8.2 percent over 2012, with transactions rising from 54 million to 58.4 million.

The 58.4 million transactions were 102.8 percent of E-470's 2013 projection of 56.8 million.

The rise in traffic, coupled with a 2013 toll increase, resulted in a 10.6 percent, $12.4 million increase to $129.2 million in toll revenue, according to the report.

Operating costs were $30.6 million in 2013, compared with the $32.9 million budgeted. The 2013 actual operating costs compare to $27.7 million in the prior year, a 10.5 percent increase. A significant portion of the authority's increased operating costs are directly related to processing and collecting the growing volume of tolls.

Stan Koniz, E-470's finance director, said in a press statement that the 10.6 percent growth in toll revenue was sufficient to meet E-470's financial obligations. Those obligations included $82.2 million of debt service payments in 2013 to bondholders. E-470 has $1.6 billion in outstanding bond debt.

Koniz said the rise in toll revenue also fully funds capital construction, enabling, among other roadway resurfacing and safety improvements, the construction of a new interchange at Quebec Street in Thornton that will get under way this spring and open in late spring 2015.

"The growth in revenue ensures we can meet our annual debt obligation to our bondholders and still have enough reserves to enable us to reinvest in the quality of the road," Koniz said. "E-470 has to deliver the high-quality experience our customers, as toll payers, have a right to expect."

E-470 is financed, constructed, operated and governed by the E-470 Public Highway Authority, which is composed of eight local governments: Adams, Arapahoe and Douglas counties, and the municipalities of Aurora, Brighton, Commerce City, Parker and Thornton.