Page 382 - 360.revista de Alta Velocidad - Nº 6

Yang, Haoran. Dobruszkes, Frédéric. Wang, Jiao’e. Dijst, Martin.

sensitive to administrative levels. Therefore, there exist stronger connections for city ends
with a rather high administrative level and long distance in airline networks.

Third, in terms of community structure, compared to airline networks without an obvious
pattern of clusters in specific regions, cities with dense populations and developed economies
along with trunk HSR lines tend to be clustered in specific regions. Therefore, it is worth
noting that agglomeration economies of urban systems could be facilitated by HSR networks,
whereas airline networks relatively contribute to a more balanced urban development by
increasing interactions especially between cities with lower socio-economic performance in
the west and ones with higher socio-economic performance in the east.
This paper opens several research perspectives. First, because long-distance transport
networks evolve over time and shape the demand to some extent, it will be of interest
to replicate our analyses for several years. Indeed, the total HSR length will extend from
19,100 km in 2016 to 30,000 km in 2020 in comparison to the total number of airports from
216 to 260 (NDRC, 2016), which means that the HSR development will be in a faster growth
rate especially in the western part of China after 2013. On the airline side, the expansion
of low-cost airlines in China (Jiang et al., 2017), even though at a controlled rate, could
also affect the pattern of domestic intercity travel. Future research after a fully complete
construction of the HSR and mature airline networks could thus shed light on updated China’s
urban systems, especially regarding that new HSR developments in western China could
play an important role in bridging China and Euro-Asian urban systems by the Belt and Road
Initiatives. In addition, future research could better consider that HSR and airline networks
are highly related to the economic process of cities nodes. Therefore, comparisons of HSR
and airline passenger flows with other socio-economic intercity flows could more clearly
illustrate the relationship between the economic networks and highspeed transportation
networks. Finally, since HSR and airline travel are mostly due to upper socialoccupational
groups, it is of interest to expand our work with intercity travel made by traditional rail
services and by road. This would arguably diversify travelers’ social –and thus spatial–
patterns. The resulting urban system would thus be more comprehensive, and comparison
of urban systems rendered by traditional/slower vs. modern/faster transportation modes
would be full of lessons to be learnt.

380 360.revista de alta velocidad