Railway/metro would be generally better used for bringing the country commuters in rather
than for hauling city-based people around town, exceptions being the Uni and Shannon
AP/Ind Estate runs.
Cutting the Tralee line at NCW and earmarking the same line as a bypass route for Adare
were cardinal errors.
Never mind the fact that a good many parts of that line needed upgrading, having a
continuous run from Limerick to Tralee and thence Fenit would always hold internal
traffic and tourist potential.
On your map there are large blocks of the city within which people would have a long old
walk to the nearest rail/metro stop.
Small local bus + rail/metro is too expensive and too slow.
Around town, I think that bus is the cheapest option.