As I mention in my prior posts, the number of smoking cars on the Tokaido Shinkansen have been limited, the newer shinkansen series N700 being released on the Nozomi services this year will have all non smoking seats. There will be small smoking compartments in some cars:
In order to actively deal with preventing secondhand smoke, all seats will be rendered
non-smoking and new smoking rooms will be established in the vestibules of cars 3, 7, 10 and 15 (6 rooms) .
- Smoking rooms will be equipped with forced smoke ventilation devices and
photocatalytic deodorizers (developed at Komakai Research Facility).
http://jr-central.co.jp/eng.nsf/english/n-06-0526/$FILE/03attachment2_n700.pdf
I wouldn't be suprised if smoking will be eliminated on all trains evenutally.
The government should ban smoking totally and make it illegal but until then, since they authorize the purchase of tobacco, they should allow smokers to travel around the country as well.
I think this is a separate topic, but here in the United States, there are many bans on public smoking and in resturants and bars (depending on where you live), smoking is banned on airplanes, and I've never been on a train yet here in the US that allowed smoking (maybe on some of the longer distance trains maybe, but I've havent been on those).