Maryland pols will probably pander to the commuter lobby anyhow. The state will spend many billions of dollars. It will not, of course, reform Davis Bacon, so much of this will go to the usual kickback arrangements. Drivers will get years of construction delays. Development pressure will mount, and Montgomery County's limits on sprawl will face every intensifying attack.
And ten years from now, if something is actually built, the traffic situation will be even worse than it is today. But a generation of politicians will have skated through the next couple of election cycles pointing the earthmovers along the road, and they will take credit for "doing something" -- even though what they are doing is wrong.
A second bridge across the Popomac would remove traffic from anywhere near Gaithersburg going to Dulles airport and many parts of northern Virginia. Is it possible that is never even considered as it would impact the homes of the wealthy people who live near the river north of the current bridge?
If the freeways were widened, but tolls were allowed across all the lanes on completion, like on the Intercounty Connector, there might be a chance of easing the problem, because an actual, direct, up-front coast would be exacted from people using the freeways for long-distance commutes, as well as short trips otherwise easily accomplished on surface streets. After all, buses and subways are also heavily tax-funded, but a direct cost (fare) is also imposed. Don’t see really long lines at the bus stops, although there are at Metrorail stops during rush hour.