Panama is a very simple linear structure along the coast. I met the Minister of Transport 15 years ago in Madrid (he came to a presentation of mine) and he took the ideas from Madrid's Metropolitan Plan to implement in the Panama Plan. I wonder if he did.
In any case, I do present a simple analysis showing that obvious structure. The width of the plain is 6 kilometers so three structural lines can be implemented: the coastal line, the foothill line, and the mid-plane one. The mass public transport as an extension of the actual 'metro' line would serve the residential TOD-BUD’s and urban developments in a double row structure.
But the real issue of Panama is how to cross the Canal to grow west. Mass public transport accessibility should be promoted and thus the priority should be to build this commuter train line rather than increasing road accessibility with an extra bridge.