Although MARC and VRE aren’t all that different, they operate totally independently of each other. Riders on one may not even be aware the other exists. This map would help change that.
The two agencies will probably never merge, but it might someday be possible to integrate their operations to work more like a single system. MARC trains might run across the Potomac into Virginia, and VRE trains might continue north into Maryland. It would be difficult but possible.
Cross-posted at BeyondDC.