# Promotion Effects of High-Speed Rail on Urban Development: Evidence from Three Lines in China
## 1 Introduction
Viewed from the spatial perspective of urban agglomerations, HSR helps promote the formation of multi-center structures, narrowing the development level gaps within urban agglomerations [26], and supports the high-quality economic development of urban agglomerations [27]. Similar to cities, the promoting effect of HSR on the economic development of urban agglomerations also shows \"heterogeneity.\" [PERSON] et al. (2021), through a comparison of the Yangtze River Delta, Pearl River Delta, and Central Liaoning urban agglomerations, found that HSR has a more significant positive effect on urban agglomerations with higher levels of economic development and spatial correlation [28]. HSR has a significant promoting effect on urban construction land development and land value enhancement. From a spatial perspective, the impact range can include the entire city and the areas surrounding the stations [29]. [PERSON] et al. (2021) used a spatial panel regression analysis method to evaluate micro-level land use data for 285 cities in China, finding that HSR plays an important role in promoting changes in urban land use structure in China, with a more significant impact on second and third tier cities [30]. Some scholars have confirmed the positive influence of HSR on urban land expansion in China and have further discovered that cities in the central and western regions and those with lower development levels exhibit a more pronounced expansion trend [31; 32]. In general, the opening of HSR stations, the increase in HSR lines, and the number of HSR stations all significantly promote the growth of urban construction land area, facilitating the conversion of agricultural land to construction land [33; 34; 35; 36]. From the perspective of land use efficiency, some scholars have assessed the impact brought by HSR and found a significant improvement, with varying enhancement effects across different types of cities [37]. From the land value perspective, HSR can bring a noticeable uplift [38; 39; 40]. [PERSON] et al. (2018) found that cities with HSR stations had an average land price increase of about 7.0% compared to those without stations, with residential land and commercial service facilities land prices rising by 22% and 11%, respectively, while industrial land prices decreased by about 17% [41]. [PERSON] et al. (2021), based on research on Japan's HSR, found that metropolitan areas experienced land price increases due to the opening of a HSR, while smaller urban areas might suffer losses due to land price declines [42]. Inrecent years, many newly built HSR stations in China are located far from central urban areas, in suburban or even exurban areas [43]. Many local governments attempt to utilize HSR stations to promote the development of new towns. Consequently, some scholars have specifically studied the impact of HSR on land use around stations. [PERSON] et al. (2015), using 38 stations along the Beijing-Shanghai and Wuhan-Guangzhou HSR lines as cases, found that the development scale around the Beijing-Shanghai HSR stations was much larger than that around the Wuhan-Guangzhou HSR stations, with a higher proportion of commercial land, which is related to the scale and economic development level of the cities along the two lines [44]. [PERSON] et al. (2022) evaluated the net effect of the Hainan East Ring HSR stations on the expansion of surrounding construction land, finding that construction land around all stations showed an expansion trend, with the two most important stations, Haikou East and Sanya, having the largest expansion scale [45]. In relatively underdeveloped regions and small to medium-sized cities, HSR new town construction is more government-led, with the lack of market forces leading to slow development of HSR new towns, making it challenging to effectively drive economic development [46; 47; 48]. Some scholars have focused on the impact of HSR on urban carbon emissions and the environment.