Twenty-five years ago, backers of E-470 offered motorists a deal some couldn’t refuse.

For a price, they could have access to a wide-open highway east of Denver unfettered by traffic already clogging public-owned interstates. Some drivers gladly took their offer, paying tolls along the start of what would become the 47-mile expressway just to skip the hassles and delays of local roadways.

“That is whole idea of what we do,” said Tim Stewart E-470 executive director. “We sell access, we sell opportunity.”

But even as E-470 enjoyed its best year in 2015 and Wednesday celebrates its silver anniversary, longtime critics say the highway locks out too many local motorists who can’t afford its price tag.

When the final phase opened in 2003, the cost for the 47-mile trip was $8.50. This year, the price is $17.45; with an ExpressToll account, it is $14.

“Most people who live in the communities along I-25 and I-225 can’t afford to get on E-470. It doesn’t seem to be benefiting them much at all,” said Greg Fulton, president of the Colorado Motor Carriers Association. “It just sits out there by itself.”

He said most local truckers avoid E-470 because the cost is too expensive. An 18-wheeler with five axles and no toll account must pay $13 for the 5-mile stretch between I-25 and the first toll plaza. The entire 47-mile stretch is $69.80 without a toll account ($1.49 per mile), or $56 with an account ($1.19 per mile).

“The highway was originally presented as a bypass so we could put truck traffic going around the city,” Fulton said. “But we haven’t had that because most trucks can’t afford to be on it.”

“You would think that one day, E-470 would want to be part of a regional conversation,” he said.

Originally derided as the “road to nowhere,” E-470 enjoyed unprecedented growth in 2015, the highway’s sixth year of a traffic uptick. Traffic, as measured by the number of toll transactions, increased from 66.4 million to 74.6 million, a 12.4 percent increase over 2014.

The steady stream of cars and trucks, coupled with a 2015 toll increase, resulted in a 15 percent increase in net toll revenues to $173 million.

The revenue jump allowed E-470 to meet its financial obligations, including $91.1 million in debt service payments to bond holders. E-470 — which receives no federal funding and no tax dollars — has $1.5 billion in outstanding bond debt.

“Our debt income ratio is good,” said Stewart. “Sure, forecasts are tricky but we’re confident where we are going.”

E-470’s revenue growth is likely being fed by lower gas prices and more commercial development along its corridor, which stretches from C-470 at I-25 in Douglas County to I-25 near 160th Avenue in Thornton, said Stewart.

E-470 can also afford an $88 million expansion of the tollway between Parker Road and Quincy Avenue from two lanes to three in each direction. It will include a multiuse pedestrian and bike trail.

The highway, managed by a group of local officials, also took steps to improve local air quality and save energy. In 2012, it installed 22 solar sites for road surveillance cameras, road signage, variable message signs and streetlights, toll collection equipment, toll plazas, maintenance facilities and its administrative headquarters.

Its ExpressToll Service Center assists Colorado’s other tolling agencies including Plenary Roads Denver, which oversees the tolling along U.S. 36 between Boulder and Denver.

“We want to be a good neighbor and our governing board wants to have a say in what goes on regionally,” Stewart said. “We are not out here by ourselves.”

The highway’s billing process for license plate tolls is “about 99 percent accurate,” Stewart said. “We can’t say we are perfect and sometimes the vehicle ownership records are not always accurate.”

E-470 proponents say the highway is a good example how local governments worked with private enterprise to improve local infrastructure. Facing the lack of state and federal funding, Adams, Arapahoe and Douglas counties joined together to form the E-470 Authority in 1985. Legislation then allowed officials to plan and finance the highway.

It has since spurred economic growth and is a reliable alternative for harried motorists, say backers.

“When it’s cold and snowing out there, you know it will be well-maintained and available for use by anyone,” said former Colorado Gov. Bill Owens.

Longtime critics, however, say E-470 has little regard for its neighbors nor local motorists.

A Facebook page titled “Don’t drive E-470, Colorado’s rip-off road” is filled with angry testimonials. Complaints are mostly about being billed astronomical amounts of money for unpaid tolls.

“I just got a bill for over $800!!!! And I never drive the stupid toll road!” said one driver.

The tolls themselves are considered among the highest in the country. A driver without an Express Toll pass, will be tolled $3.25 between Chambers Road and Peoria Street. Tolls go up to $3.55 at the other four toll plazas, totaling $17.45 start to finish.

Still, drivers such as Dr. Richard Nelson see E-470 as an enormous asset.

“It was just so much faster, so much more of a wonderful convenience,” said Nelson, who was one of the original drivers to hop on the first segment of C-470 when it opened in June 1, 1991. “My wife said it would never take off but look at it now.”