Greg Hinz at Crain's reports that CMAP is pushing a "Fund 2040" quarter-cent sales tax for the six-county area to help implement their GOTO 2040 plan. Reportedly this would generate about $300 million annually for transportation, water infrastructure, and open space projects, which would be doled out through a competitive process and not based on a pre-determined list.
$300 million per year is about half of what LA County receives from their half-cent Measure R sales tax, for comparison, so we could see a handful of ambitious projects financed this way, including the Red/Purple Line Modernization project or some of the stuff in CREATE, especially if used to secure Federal matching funds. That dollar amount could go up, too, if Rauner's proposal to extend sales tax to services goes through.
I do not think this is enough money to implement the ambitious Measure R-like "Transit Future" proposal, but maybe a few key elements from that plan could move forward.
http://fund2040.org/