Thanks to all who responded to my single/double track questions. It does seem like a reasonable option.
Talindsay, what did you mean by this comment? I'm not seeing how the bicycle coordinator relates to no rapid transit in the greenway. Nor do I understand what you mean by the double/single streetcar not precluding rapid transit buildout later. Could you elaborate?
Sure, I'll be glad to. The Greenway has quite a lot of ROW, but it's chopped up funny with the old bridges, the sloping sides, the bicycle path, and at places, the odd shifts of the various elements within the ROW. In order to fit full double-tracked rapid transit into the space available, they would have to either (1) remove or drastically narrow the bicycle road; or (2) rebuild several bridges in tight spots, and square off the sloping sides of the Greenway. The latter is not only cost-prohibitive right now, it also probably couldn't pass an environmental review because the bridges are considered historic structures that can only be replaced if they reach some critical structural deficiency levels.
So, given current constraints, only by substantially reducing the bicycle amenity in the Greenway could they fit double tracks in there given current other constraints. The mayor's decision to substantially raise non-motorized transportation's stature in the city bureaucracy clearly indicates a policy shift on the city's part that will preclude substantial reductions in the bicycle amenity, and hence it's not really feasible to imagine the city approving a double-track line at this time.
The single/double arrangement is, in my opinion, a very good interim solution, but it *is* an interim solution; it will provide significant mobility improvements in my opinion, but it will not achieve the levels of service necessary to be deemed rapid transit in a meaningful sense of the term. However, establishing the line's presence in the Greenway and establishing a significant user base for it should go a long way towards making its expansion into a true rapid-transit line more likely as the bridges get replaced and/or the Greenway bicycle path gets supplanted by other city priorities. Also, the single/double plan advanced by the Greenway coalition had the added benefit of being *very inexpensive*, which should help it move forward. Incremental improvements, aligned with bridge replacements and/or other shifts in Greenway use planning, will also be affordable and can improve service quality incrementally as the Greenway continues to evolve.