A sure way to begin holding the line on greenhouse gas emissions and oil dependency is to reduce the rate of growth in gasoline usage and eventually to start reducing total gasoline usage.
From Texas this good news:

State transportation officials announced today that rising costs, dwindling federal funds, and lawmakers’ opposition to private-sector investment in toll projects have combined to force it to sharply scale back construction plans.
“The people of Texas need to understand that within a very short period of time, there will be no money for mobility projects,” said Texas Transportation Commission member Ned Holmes of Houston.
The affected projects will be those designed to build new roads, or add lanes to existing roads. Projects already under contract and those designed to maintain or rehabilitate existing roads won’t be affected.

Yep, stop building new roads to reduce the growth rate in fuel consumption.