Light rail works only where it substitutes for a viable or potentially viable high-density bus service, or breaks a significant bottleneck for a lot of people. To have any hope of making sense on the Monterey line it would have to go into Cannery Row if not P.G. itself (pigs in ... see above) and the other end needs to be not Castroville but Salinas (i.e. hang a right at Marina). That would at least cover one of MST's trunk bus lines. But even though it would potentially serve the majority of Mon.Co's urban population it'll never meet Federal ridership standards for rail so it'll have to be funded locally. Good luck.

Light rail is an urban/suburban transit mode. It doesn't work for longer trips (which is the real reason why SMART as LR made no sense) - too slow and uncomfortable - or very short trips - too clumsy as a streetcar. Figure lines up to about 25 miles, with most trips using the line shorter than that. Trips average 20-25 mph overall, compared to 10-20 for streetcars/urban buses and 30-50 for commuter/heavy rail.

Given the other characteristics of the area (NIMBYs galore, rare everything, Coastal Commission (see NIMBYs), little traffic congestion, little transit use, etc.) this is really just another pipe dream. Even SMART makes more sense. Figure on extending the bike lane, which is more fundable in a reasonable timeframe.