I haven't been blogging much lately, because it's conference season, road warrior time (or transit warrior, or airport...). Airports are implementing satellite-based air traffic control systems. Tolling entities are discussing open-road tolling, privacy issues and pricing. Bridge engineers are talking everything from anti-corrosion technologies to hot-dip galvanizing to carbon nano-tubes and balsa sandwich core plate systems. Ah, variety.

But as I went from Dallas (American Association of Airport Executives) to Washington, D.C. (Womens Transportation Seminar) to Boston (International Tunnel, Turnpike and Bridge Association) and now to Pittsburgh (International Bridge Conference), I noticed a common theme: The way we fund our airports, highways, bridges and transit programs is rapidly becoming obsolete.

At the IBTTA, the overarching theme was about how the traditional funding mechanism, the gas tax, must be replaced by a vehicle-miles-traveled fee.

Just yesterday at IBC, one engineer told me he was wary of the idea of privatization coming into public projects. At IBTTA, one of the members of the private concessionaire that built the South Bay Expressway informed me that they had filed for bankruptcy and were embroiled in legal battles with the contractor.

At WTS, where one might assume a bit of a Democratic bent, hearty criticism of the Administration's apparent lack of leadership role in transportation was voiced.

Jayetta Hecker of the Bipartisan Policy Center (nice to see something that's bipartisan these days) noted that the voter-approved sales tax increases that recently funded so many transit projects is not sustainable. And in a struggling economy, that's proving true as Congress discusses emergency funding for a dozen agencies.

And airport officials are enjoying a lively debate over the airlines' opposition to raising passenger facility charges from $4.50 to $7. Here again, the notion of the user (including the airlines as well as the passengers) paying for what they get in terms of infrastructure facilities is at play.

Tax, user fee, surcharge, toll? The word "tax" is anathema to a lot of people right now. Experts across the modes point out that in other advanced nations, citizens pay plenty for their high-speed trains, high-tech airports and highways - be it at the pump, under the tolling gantry or in the ticket fee.

Public-private partnerships are a promising notion, but not for all projects. Best-value-based bidding, accomplished in various delivery models, is growing somewhat in popularity.

But something fundamental has to change in the national transportation model. Everyone's doing a lot of talking, but opportunities for action seem limited, especially in a political arena besieged not only by oil disasters, global tension and financial woes but bitter internal acrimony.

Transportation experts in the U.S., Democrat and Republican alike, have reluctantly concurred that an increase in the fuel tax here is needed, if only as an interim bandaid, as the industry cautiously edges closer to a user-fee-based model.

But the chances of that happening in this atmosphere are about as likely as me getting fed on my flight home tomorrow.

No method for moving forward will be perfect. But something's got to move. As the bridge folks might say, it's time to get galvanized.