Everyone is rightfully joyful re: the Monday reopening of a fabulously refurbished Government Center T station in the heart of downtown Boston. Now! What about those other transportation milestones the region could desperately use? Here are five:

The Red Line Farther Out Than Alewife

Back in the 1980s, it was assumed that the Red Line would keep going after Alewife, perhaps as far out as Route 128. Thanks largely to locally based federal bigwigs such as House Speaker Tip O'Neill and Sen. Ted Kennedy, there was enough money for at least stations at Arlington Center and Arlington Heights. Local opposition kiboshed the plan.

Given the ever-escalating cost of housing the closer one slouches toward Boston proper, a Red Line running out to less expensive areas would be a real game-changer (we think—this is all predicated on the T running good year-round). As it stands now, this is the pipe dream of the bunch, with no serious planning or work underway.

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A Connection Between South Station and North Station

Why has this not happened? Two of New England's busiest stations remain frustratingly separated in any direct sense. Connecting North and South stations would not only link up every T line save the Blue, but would ease connections for commuter-rail and Amtrak riders.

Solid proposals have surfaced now and again to connect the hubs, the most interesting of late one that would snake a monorail through the Greenway. Stay tuned.

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Chelsea Gets the Silver

Plans have long been on the table to extend the Silver Line's rapid-bus service to connect Chelsea to East Boston, downtown Boston, and the Seaport District (with a little help from the Blue Line's Airport Station in the case of Eastie). This involves creating four stations as well as relocating the current Chelsea commuter-rail station.

Work is proceeding. The Washington Avenue Bridge in Chelsea has been closed since May 2015 for demolition-slash-reconstruction work. Construction on the the commuter-rail relocation is expected to start this year and on the new stations next year.

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Commuter Rail Runs Down the Coast

Efforts to create a commuter-rail branch from South Station to Taunton, New Bedford, and Fall River—and points in between—have percolated pretty much since the service to those South Coast cities stopped in the very late 1950s.

After fits and starts in the 1990s and 2000s due largely to ballooning cost estimates, things really picked up the last several years with tens of millions in construction contracts doled out amid hundreds of millions in fresh funding.

As far as actual progress, that's another matter. Infrastructure work, including the replacement of four bridges along the future 52-mile route, is underway. Otherwise, there's no set date for the the South Coast Rail's completion because there's no assurance the funding will be in place down the road.

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The Green Line Through Somerville

With serious funding and political capital galore, this project seemed at the start of 2015 to be a slam dunk, a fait accompli, stick a fork in it/it's done: the extension of the Green Line through Somerville and into Medford, with the creation of six stations and a relocation of the current Lechmere one.

Then. Estimates of massive cost overruns and allegations of spotty management brought everything to a near-standstill by the end of 2015. The Green Line extension, which the City of Somerville and the real estate industry have been cheering for years, now appears mired in an almost-terminal decline.

Cutbacks, including in the scope of the new stations, are the order of the day as is the possibility that the whole thing could be scrapped. Meanwhile, ancillary work, such as infrastructure upgrades along the proposed route, is proceeding.