Third-rail systems are not considered obsolete. There are, however, countries (particularly Japan, South Korea, Spain) more eager to adopt overhead wiring for their urban railways. But at the same time, there were (and still are) many new third rail systems built elsewhere, including technologically advanced countries (e.g. Copenhagen Metro, Taipei Metro, Wuhan Metro). Bottom powered railways (it may be too specific to use the term 'third rail') are also usually used with systems having rubber-tyred trains, whether it is a heavy metro (except two other lines of Sapporo Subway) or a small capacity people mover (PM). New electrified railway systems tend to use overhead for regional and long-distance systems. Third-rail systems using lower voltages than overhead systems still require many more supply points.