The decline in driving makes the gas tax less reliable as a transportation funding stream. VMT graph: FHWA.

One
of the big challenges that federal policymakers will soon have to
address is how to pay for a new generation of transportation
investment. The federal gas tax, pegged at 18.4 cents per gallon since
1993, just isn’t up to the job in its current form. There’s a whole range of ideas on the table to fix the problem, and in this week’s StreetsWiki entry, John Boyle, advocacy director for the Bicycle Coalition of Greater Philadelphia, points us to a potential revenue stream for transit, smart growth, and bike-ped projects:

The Clean Low-Emissions Affordable New Transportation Equity Act is
a bill that sets aside revenue from a cap-and-trade program in a future
climate bill towards green transportation projects that reduce greenhouse gases. CLEAN TEA was introduced in the House of
Representatives in the 2009 session as H.R. 1329 and in the Senate as S. 575.

Under
CLEAN TEA, ten percent of the revenue would be used to create a more
efficient transportation system and lower greenhouse gas emissions
through strategies including funding new or expanded transit or
passenger rail; supporting development around transit stops; and making
neighborhoods safer for bikes and pedestrians.

CLEAN
TEA is contingent on some pretty big ifs, like whether a cap-and-trade
program will make it through Congress. But the Obama administration
projects raising $80 billion a year
from auctioning off carbon emissions permits, and CLEAN TEA has
sponsors from both parties in the House and the Senate, so this is
definitely an idea with some momentum.