Every time I see rust on a bridge (and many other places, but especially on bridges), I keep thinking "Why aren't they doing basic, long-term maintenance?". If they're planning on just running the system into the ground and letting it fall apart, then nothing matters, but that just can't be! Can it? But if they plan on long-term viability for the train system, then how can they let the steel structures rust/rot away? For short-term profit? It's far more expensive to build a new bridge than it is to maintain an existing one through repainting it, etc.
It can't be (can it?) that they are sabotaging the future of Japan's rail system for the sake of STP (Short Term Profits)! The situation seems symptomatic of so much that is going wrong in the world now - basically sabotaging the future for short-term savings/profits.
Priorities... the railways have spent a lot of money installing elevators and escalators at all the stations (no mean feat, that, given the vast scope of the Tokyo train system), and now that the economy is is doing badly, a lot of advertising spaces are going unrented. I can't know what is going on management-wise in the offices of the railways, but could it be that due to lower revenues than expected, they are putting off expensive maintenance in the hope that the economy will improve before the bridges become so rusted that the rail lines have to be shut down for safety reasons?
If this is the case, it seems like a fool's gamble to me. Any rust on a steel structure means it is that much weaker than before part of the steel rotted. Hard times or no, painting vital steel bridges should be a non-negotiable absolute must-be-done priority! If there isn't money, the suits should get out of their worthless meetings, put on overalls and grab some paint brushes! I think. I'm only saying this because I have great respect for Japan's rail system and want to see it stay in great shape!
Lyle (Hiroshi) Saxon