## 2 Literature Review
### Dynamic of the Population  
The regional interconnection of HSR service networks is their most important attribute. One of the major factors determining the ease of accessibility is public transportation, along with spatial, temporal, and individual variables [23]. It helps increase the level of community integration and gives advantages to people in surrounding communities. Dynamic of population is connected to the accessibility of urban development, relocation and other major elements of human life such as accommodation and work [23; 24]. When Japan launched its Tokkaido Shinkansen service, it was found that there was a population growth of 22% in cities with train stations. This was an increase of 16% compared to the cities without HSR stops [24; 25]. One half of the areas with HSR stations showed population increase higher than the national average. In Tohoku Shinkansen, cities near HSR stations had a 32% population rise, while areas without HSR services saw no significant population growth [26].  
In Spain, residents prefer to stay in Ciudad Real, a big city. The impact of Spanish HSR illustrates by solid demand for housing near HSR stations. The reason is that the service offers travel options between the city and other major cities [27; 28; 29; 30]. Moreover, Swedish HSR has shown that the network has attracted more citizens to live in the outlying town of Eskilstuna with a HSR station providing good links to Stockholm [31].  
Studies have shown the benefits of greater accessibility via the time-space convergence effect, which may be seen as a consequence of regional expansion [25]. HSR services also create regional spatial inequalities since the inhabitants' areas with HSR stations offer better QoL due to longer-term connections [6; 32; 33].  
As for the labour force and employment, both of these are major factors relating to population dynamics. Many researchers have pointed out that HSR services directly impact an area's employment rate and economy. Additionally, the size of the labour force has been found to have increased after the implementation of HSR services as they offeraccessibility between workplaces and residential areas. In Japan, some employment sectors, such as food retailing and accommodation, showed significant benefit from Shinkansen services [34; 35].  
In Europe, most HSR stations are in cities, connected to city-wide transit systems. For this reason, European networks are more accessible and beneficial to employment [36]. Similarly, HSR services have been related to job opportunities in cities. For example, more than 22,000 positions will be hired along with the High-Speed 2 (HS2) line by 2026 [37]. Moreover, 100,000 more jobs were expected with the Atlantic HSR in Spain [38]. Scholars have researched the French LGV on growth, with some measurements of the impact being in-depth, looking at employment density in suburban areas [39]. The findings clearly indicate that the number of job possibilities has grown across towns with HSR; on the other hand, non-HSR cities are showing growth in the job market. Therefore, expanding job opportunities can be linked to other factors.  
HSR services bring positive effects for local businesses and the economy. The opening of HSR lines provokes investment in various businesses such as real estate, tourism and community facilities. HSR services contribute more to the limited supply than air services [40]. This is not only through a reduction in travel costs, but these services still reduce travel time. This becomes a crucial tool for increasing the potential of local markets, especially for the services sector, such as marketing. In addition, another research states that reasonable travel costs can enhance local benefits. This is because urban productivity and economic activities can be spread to neighbouring areas, where people can be reached by HSR networks [41].