Denver Mayor Michael Hancock took advantage of the commemoration of the opening of RTD’s new light-rail platform at Union Station this morning to reiterate his pledge to complete the massive FasTracks transit expansion.

“My hope is that we go to voters in 2012,” Hancock said of the possibility of asking voters in the eight-county Denver metro area to double the existing 0.4 percent FasTracks sales tax. The mayor discussed the tax in a post-ceremony interview with The Denver Post.

Of a possible vote next year, the mayor acknowledged, “We have to build a best case for it.”

Hancock said among the factors public officials will weigh as they consider a tax vote are the state of the economy and what competing measures may be on the 2012 ballot.

Voters approved the original FasTracks tax in 2004, but since then lower-than-anticipated tax revenues and higher-than-expected construction costs have combined to leave the project more than $2 billion short of what is needed for completion.

“We will aggressively pursue all types of funding before going back to voters,” Regional Transportation District General Manager Phil Washington said at this morning’s ceremony.

Hancock and other officials arrived at the new light-rail station around 7:40 a.m. on a train from the Pepsi Center. Speaking of other planned elements of the $489 million Union Station redevelopment, the mayor said, “Very soon I want to take that 28 minute ride to DIA. That will continue to transform the entire region and connect Denver with the rest of the world.”

The construction tab for the new light-rail station is about $37 million, but the Denver Union Station Project Authority also is spending $113 million on a commuter-rail facility just outside the west doors of historic Union Station.

RTD expects to start construction in earnest soon on the $1.1 billion East Corridor commuter train to Denver International Airport. It is due to open in 2016.

In opening the new light-rail platform at Union Station, RTD restarted service on its Central Platte Valley rail line that had been closed for the past three weeks for various construction projects, including the move of the light-rail station about two blocks west from its old location.

RTD also extended its 16th Street Mall free bus shuttle today to serve the new station.

“It’s an easy transition,” said Kelsey Ripley as she arrived on an E line train at the new station around 7:50 a.m. Ripley and a fellow commuter, Kelly Schaible, work only a block away at Gates Corp.

A short time later, arriving passenger Barb Nisley said of the new station: “It’s beautiful.”

“It’s a block further than I typically walk,” said Nisley, who works at the U.S. Environmental Protection Agency’s office at 16th and Wynkoop streets. But Nisley wasn’t complaining.

Some transit advocates have complained for years about Union Station redevelopment designs that placed the light-rail platform further from the historic station.

The Union Station project authority is building a $177 million underground bus depot that will link the light-rail platform with the commuter-rail terminal adjacent to the old station.

“It’s not bad at all,” arriving light-rail passenger and attorney Andy Rottman said this morning, as he hopped the Mall bus shuttle to get to work. Rottman’s law office is at 17th and Market streets.

Jeffrey Leib: 303-954-1645 or jleib@denverpost.com