When a politician like Maryland Governor Larry Hogan kills off a transit project, not only does he rob citizens of anticipated improvements, he could be wiping out decades of intricate planning.

Dan Malouff at Greater Greater Washington notes that by 2019 it will have taken 34 years to complete the Metro’s Silver Line, which will connect DC and suburban counties with Dulles Airport.

Malouff explains the above graphic:

The timeline begins in 1985, when the idea of a Metro line to Dulles Airport went from vague concept to serious planning initiative following a study that determined it would be feasible.

Planning (yellow on the timeline) and environmental work (green) took the next 21 years, until 2006. It took another 3 years for officials to finalize funding (blue) before construction (purple) could begin in 2009.

Plopping a rail line down the middle of a gargantuan suburban highway with a capacious median is easy compared to putting one virtually anywhere else. Almost any other potential Metrorail expansion imaginable will be harder to plan, fund, and build.

“That doesn’t mean it’s not worth doing,” Malouff writes. “But it’s definitely going to be hard.”

Elsewhere on the Network today: Streets.mn tests whether motorists are yielding to pedestrians; and Biking Toronto reports that there is fresh green paint, but no physical separation, on a much-needed bike lane.