Mediumand lowvolume rail transit, as a supplement to metro networks in super or mega megacities and as the backbone of large and mediumsized cities, is essential for solving urban traffic problems. Based on a survey of more than 2600 mediumand lowvolume rail transit operation lines in 496 cities in 65 countries, a database of mediumand lowvolume rail transit lines worldwide was constructed. Based on this database, 9 types of mediumand lowvolume rail transit systems (gear rail, tram, suspended monorail, automated people mover systems (APM), straddle monorails, linear motor systems, mediumand lowspeed maglev, electronic guidance rubbertired system, and beamguiding rubbertired system) have been obtained worldwide, with a total length of 18 744.84 km. And statistics were conducted on the distribution of mediumand lowvolume rail transit in various continents and countries. The results showed that it is mainly distributed in 32 countries in Europe, including Germany and Russia, with a total length of 13 256.0 km, accounting for 70.7%. Statistics show that the distribution of various rail transit systems in different countries/cities, with different urban characteristics and functional positioning of different lines shows that mediumand lowvolume rail transit systems mainly serve cities with a population of less than 3 million. 76.25% of tram lines, 47.82% of straddle monorail lines, and 42.11% of linear motor system lines are backbone lines, 84.62% of gear rail lines are tourist lines, and 70.73% of APM lines are airport dedicated lines. Additionally, the origin and development of each system are summarized, and the technical characteristics, parameters, and applicability of each system are analyzed. The results provide a reference for the selection of urban medium and lowvolume rail transit systems in China.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |