Most cures for congestion come in billion-dollar packages, since it's easier for politicians to evade hard choices by instead throwing lots of money at the problem. An example of a simple, cheap (but politically radioactive) cure for congestion is to start replacing curbside parking with lanes for buses, bikes, and pedestrians. A pithy case for doing just that, as New York is trying to do, is "No Parking, Ever'" by Hope Cohen, deputy director of Manahattan Institute's Center for Rethinking Development. It's full of common sense.
First of all, not all parking lanes. Cars get shifted to narrow streets of the residential areas (first political fire alarm); or, you might do as they do in Europe and convert vacant lots into cheap car-parks. Secondly, there's some shared sacrifice, such as banning sidewalk cafes in very congested areas and eliminating some bus bulbs. We'd probably have to allow the parking lot barons to build more ugly garages.
The political objections accumulate from lots of vocal groups, such as merchants or the anti-car crowd (who fear more traffic mobility), but the benefits would be very broad. Bus rapid transit, for instance, the usual preferred solution over light rail, can only really be rapid if buses have exclusive lanes. Take those lanes away from cars and you have a big fight. So take them away from parked cars. Same with bike lanes.
But just try. Mayor Paul Schell, as I recall, got this idea and managed after much arm twisting to get maybe two blocks, on Madison near Boren, freed up. The current battle is along Aurora, which hopes to free up lanes for bus rapid transit and is running into howls from merchants. The next battle will be downtown, where the alternative solution to a new Viaduct is to put more north-south traffic coursing through Western, First, and Second Avenue, gaining that capacity by erasing curbside parking.
It probably won't happen, and we'll all blame the spineless politicians. But the fault lies with us, not having put together a coalition to push for such a simple idea. And one more thing: There are no real economic beneficiary groups for such a simple, low-cost solution, except maybe parking lot operators (whom we must scorn). Compare that to the economic interests in light rail, and you get an idea why good, affordable, commonsensical ideas are so often doomed.