The cost of building and maintaining a 2.5 foot wall next to the entire rail line is likely a rounding error compared to the cost of upkeep of the rail line and

The cost of building and maintaining a 2.5 foot wall next to the entire rail line is likely a rounding error compared to the cost of upkeep of the rail line and trains. In other words, trivial sea level rise is a non-issue economically. To me the bigger issue is wetland loss since flood walls will likely prevent the replacement of higher-elevation wetlands.