“Forget the difficulty of finding the money to get FasTracks built,” writes Kevin Flynn at Inside Lane. “RTD’s bigger problem now is finding the money to be able to operate the rapid transit expansion after its planned 2017 completion.”

The prognosis comes from officials who point out that although the cost of building FasTracks has decreased by $512 million because of recessionary deflation, RTD’s ability to pay for the ambitious metro rail system has suffered more as sales taxes lag. There’s now a budget gap of more than $2.4 billion. That means the construction of the system could be delayed, as RTD’s board of directors seem inclined to debate not whether to ask voters for a tax hike, but when they will do so.

RTD General Manager Phil Washington has presented potential scenarios for FasTracks, reports The Denver Post, including one in which RTD would wait until 2012 to take a tax increase to voters. If voters approve one at that time, the entire project can be completed by 2019, assuming receipt of the $1 billion in federal funds.

RTD Board Chairman Lee Kemp tells the Denver Business Journal that RTD remains committed to finishing FasTracks.