Senate Democrats huddled behind closed doors this afternoon to assess their options for a new job-creation bill, with one option of around $80 billion making headlines even second-ranked leader Dick Durbin (D-IL) warned that no details are set in stone.

Senate Majority Whip Dick Durbin (D-IL) (Photo: STLToday)

But as Democrats debate the wisdom of tax credits for new hiring and clean energy production, the bill’s infrastructure spending provisions could be subject to less tweaking. So what do they look like?

A knowledgeable source tells Streetsblog Capitol Hill that the jobs bill outline currently under consideration in the Senate includes $14 billion for roads and $7.5 billion for transit.

Such spending levels would be a far cry from the transit industry’s preferred investment of $15 billion (backed by Kirsten Gillibrand, New York’s junior Democratic senator), but a more favorable ratio than the House approved in its jobs bill last month.

The Senate is also mulling $2.5 billion for rail in its jobs bill, which could provide yet another down payment on bullet train projects such as the one President Obama is expected to unveil in Florida this week.

Of course, Durbin’s caveat remains firmly in place — these numbers are an early projection, subject to change as Democratic leaders gauge support within their ranks. A final version of the jobs bill could hit the Senate floor before the President’s Day recess next month, but it’s likely to take longer for the measure to be reconciled with the House version.