The word on the street is that after some small victories in the House ($3B added to capital funding for transit) there will be another fight in the Senate where various amendments are being proposed to strip transit funds and move them to highways, or to simply add $50B to highways.
Meanwhile the New York Times is underscoring the lack of operating dollars for transit, so that at a time when ridership is up nationwide, transit systems in many cities are cutting service.
Into this mix, the indefatigable Todd Litman has produced a report contrasting the stimulus effects of spending on highways and transit (PDF 372K).
My favorite part of the report is a chart tracking the return on investment for highways over time:
This seems to paint a clear story to me – we have achieved the economic benefit of a fully-built out highway system and every dollar of new capital (not maintenance) faces diminishing returns.