Transportation funding advocates say they will try to persuade lawmakers during the lame-duck session to restore authorized surface transportation funding that was dropped from the stopgap spending bill the Senate is set to clear this week.

The continuing legislation that would fund the federal government for the next six months does not include more than $500 million in surface transportation funding authorized in the recently enacted highway law (PL 112-141). Transportation advocates say they will seek either an omnibus spending bill or a stand-alone Transportation-HUD appropriations bill that would restore the funds.

“When you return following the November elections, and conclude action on fiscal year 2013 appropriations, we strongly urge you to honor the funding levels established by [the surface transportation authorization] which merely maintain baseline funding for the first year,” John Horsley, executive director of the American Association of State Highway and Transportation Officials, wrote in letters addressed to House Speaker John A. Boehner, R-Ohio, and Senate Majority Leader Harry Reid, D-Nev.

The spending resolution would slice fiscal 2013 highway formula spending to $39.1 billion from the level of $39.7 billion as authorized by the surface transportation bill, effectively eliminating a small increase to offset inflation.

Senate Environment and Public Works Chairwoman Barbara Boxer, D-Calif., said last week that the funding should be “honored for fiscal year 2013.”

House Republicans pointed blame at the Senate, noting that its fiscal 2013 Transportation-HUD spending bill (S 2322) has never advanced beyond subcommittee.

A spokesman for House Transportation and Infrastructure Chairman John L. Mica, R-Fla., said the appropriate spending levels would be “overridden when a full-year transportation appropriations bill is enacted.”

Besides the continuing resolution, another threat to the recently authorized surface transportation is the automatic spending cuts under sequestration that will take effect unless Congress reaches a budget deal by the end of the year.

According to projections of across-the-board cuts the Office of Management and Budget released last week, a transfer from the general fund to the Highway Trust Fund in fiscal 2013 would be reduced by $471 million. The loss of that money could hasten the demise of the Highway Trust Fund, which depends on motor fuels tax receipts that can no longer keep up with spending needs.

A version of this article appeared in the Sept. 19, 2012 print issue of CQ Today