The Reason Foundation's Bob Poole cheers proposed legislation from Texas's Sen. Kay Bailey Hutchison to allow keep its own gas tax money and opt out of the federal Highway Trust Fund, using its own money for its own road infrastructure needs. Some reasons:
A key rationale for devolution is that the funding approach developed to build the Interstate system is now obsolete. That approach transfers large sums from larger and fast-growing states to smaller and slower-growing states. And states like Texas end up subsidizing other states. That is exactly backwards of what a real user-fee system would do—which is to generate and spend large sums in the places with huge problems of congestion and insufficient highway capacity. A side benefit of devolution would be the elimination of tons of pork, as members of Congress would no longer be able to earmark pet projects that are political winners but economic losers.
But there are some potential hazards to devolution as well on "e pluribus unum" grounds, Poole notes:
The downside is that the Interstate system is critically important to interstate commerce, and the federal government has a constitutional responsibility to ensure that states do not erect barriers to interstate commerce….But this doesn't have to be an either/or proposition. Congress could enact standards for the Interstate system as a condition of approving devolution—things like nationally inter-operable electronic toll collection, pavement quality, bridge clearance heights, etc.—that states would be required to adhere to.
The Austin American Statesman with some details about the proposed S. 903. For more recent blogging on infrastructure issues, see this which implies that our nation's bridges aren't in as shabby shape as you might be lead to believe.