Traffic grew for the third straight year in 2011 to 52.1 million toll transactions from 51.3 million transactions in 2010, according to the E-470 Public Highway Authority. It was the second-highest traffic level next to a 54.1 million toll transactions in 2007.

Officials attributed the $13.4 million jump in 2011 revenue to growing traffic, combined with a 2011 increase in the toll charged to motorists who are billed by their license plate. Motorists tracked by transponder devices pay a lower toll.

E-470 was also able to save 7 percent, or almost $2 million, in operating costs last year, officials said.

E-470 Finance Director Joe Donahue said the growth in toll revenues was enough to meet E-470’s financial obligations, which included a $65.2 million debt service payment to bondholders. E-470 has $1.5 billion in outstanding bond debt.

Donahue said the rise in revenues also boosted the authority's capital construction fund, helping pay for other roadway resurfacing and safety improvements. This included covering the $14.5 million cost of a 2012 project to reconstruct 2.5 miles of the oldest section of E-470, which opened in 1991.

The E-470 toll road runs along the eastern perimeter of the Denver metropolitan area. The road is financed, constructed, operated and governed by the E-470 authority, which is comprised of eight local governments: Adams, Arapahoe and Douglas counties, and the municipalities of Aurora, Brighton, Commerce City, Parker and Thornton.