More conservative GOP lawmakers started raising questions about the size and cost of the measure, as well as how it would be paid for.
Other Republicans didn't like how close oil drilling might come to the Florida coast, with memories of the BP oil spill still fresh in their minds, just one of many provisions that drew some internal GOP scrutiny.
House Transportation Committee Chairman Rep. John Mica (R-FL) told reporters just off the House floor that everything would be worked out later in the month - but his "What me, worry?" explanation didn't really square with stories from individual lawmakers.
Over on the Senate side of the Capitol, the Democratic version of the highway bill wasn't making much headway either, as Sen. Rand Paul (R-KY) gummed up the works with a solo filibuster, demanding a vote to cut off aid to Egypt.
But while Democrats complained about the delaying tactics by Paul, they weren't really ready to forge ahead on the bill because of Republican amendments on other issues, like contraceptive coverage in the Obama health law and much more.
So, Senate Majority Leader Harry Reid "filled the tree" to block GOP amendments, as the World's Greatest Deliberative Body ground to a halt again.
For those of you who might be parliamentary geeks, here's the summary of Reid's motions on the highway bill:
• Reid amendment to insert Banking, Finance, and Commerce titles. (#1633)
• Reid second-degree amendment to Reid amendment #1633, to change the enactment date. (#1634)
• Reid motion to commit S. 1813 to the Committee on Environment and Public Works, with instructions to report back forthwith with an amendment. (#1635)
• Reid amendment to Reid motion to commit (#1635), of a perfecting nature. (#1636)
• Reid second-degree amendment to Reid amendment #1636, of a perfecting nature. (#1637)
This isn't the first time the highway bill has been dealt with this way. Just do a little Googling, and you find in 1997 that Senate Majority Leader Trent Lott - a Republican - used the same tactics to try to force action on a major transportation measure.
(I know it drives some of my readers crazy, but that is a reminder that both parties love to complain about the tactics of the other side while trying to convince voters they would never do the same thing.)
Meanwhile, the one thing that was supposedly going to be pushed through the Congress this week - the extension of a payroll tax cut through the end of the year - also ran into trouble late on Wednesday night.
While a tentative deal had been worked out, some in both parties were pushing back against the details.
Some Democrats didn't like a provision that saved money by making federal workers chip in more for their retirement pensions.
Some Senate Republicans were a bit peeved that they weren't part of the decision on Monday by House GOP leaders to give up on budget cutting offsets to pay for the payroll tax cut extension - and so they were withholding their support for the final deal.
And as the hours ticked by on Wednesday, that bipartisan opposition was preventing a final deal from being sealed, leading to finger pointing by congressional aides in both parties.
"Deal is a deal," tweeted a spokesman for Speaker John Boehner Wednesday night, as the spokesman for Senate GOP Leader Mitch McConnell highlighted a story about Democrats balking at the agreement.
The view from the other side of the coin was a bit different.
"If I set the over/under on the number of Senate Rs who will sign the payroll conference report at zero, would anyone take the over?" tweeted the spokesman for Sen. Reid.
"Why won't a single Senate Republican sign a conference report that Boehner is asking his House Republicans to vote for?" added the spokesman for Sen. Charles Schumer (D-NY).
But as the clock neared midnight, the haze of the partisan jabs cleared long enough for negotiators to shake hands on a payroll tax cut deal. The final agreement included a modified plan on federal worker pensions - only new hires for Uncle Sam will have to pay more into their retirement funds.
As I type this at 1:01 am, we're still waiting for all of the final details to be posted.
Just another wacky week in the Congress.