Car use has changed daily activity travel patterns, which cause serious urban problems including air pollution, traffic congestion, road accidents, and community severance. Particularly in China's rapid suburbanization, car use and related social and environmental issues are attracting great attention. Previous research has illustrated the importance of the built environment and car ownership on daily car travel distance. However, it is still not clear how car ownership and car use impact individual behavior, and the ways researchers measure the contextual influence of the built environment are not consistent. Most of the existing literature only uses residential area as the geographic context to study the impact of built environment, and only a few studies focus on workplaces or other destinations. In recent years, the uncertain geographic context problem has come under intense scrutiny by geographers seeking to elucidate the interaction between urban space and individual behavior. According to this phenomenon of the uncertain geographic context, travel behavior is influenced not only by the origin and destinations of trips, but also by the travel routes and the surrounding activity spaces. However, so far few studies have been conducted on the impact of activity space. Based on a GPS-facilitated activity-travel survey dataset collected in the Shangdi-Qinghe area in Beijing in 2012, the present paper studies the relationship between the built environment and car travel behavior of suburban residents on weekdays. To understand the importance of geographic context, three types of geographic context are used: residential area, work location and activity space. The impact of the built environment on car travel distance in daily travel, commuting travel and non-work travel is analyzed using three sets in a linear regression model. The study finds that the impact of the built environment on car travel behavior depends on travel mode and geographic context, and the built environment in work locations and activity spaces has a larger impact on car travel distance than that in residential areas. The built environment in residential areas has an influence on daily travel distance, but lower development density and better residential accessibility in residential areas can reduce car travel distance in commuting. Higher development density in both work locations and activity spaces is related to longer car travel distance in daily life, commuting and non-work travel behavior. Contrary to the findings of Western studies, better accessibility to public transit leads to more car use in non-work travel. This paper discusses the importance of the uncertain geographic context problem, indicating that activity space plays an important role in daily activity travel behavior. These findings have key implications for policy-making decision. The built environment should be a great concern in policies aimed at car use limitation.

With the rapid urbanization and motorization in China, the increasing car ownership promotes the dependence on automobile commuting, and hinders sustainable development and leads to serious traffic congestion and environment pollution as well. Based on the questionnaire survey from the residents in the central city of Shanghai, a multinomial logit model was applied to explore the impact of built environment on residents' commuting mode. It is concluded that the urban built environment has a significant effect on the choice of motorized commuting. Specifically, after limiting other factors, improving population density, mixed land use and the proportion of crossroads in residential areas may help refrain the choice of automobile commuting, while urban built environment of employment areas has less impact on residential choice commuting mode. Besides, the built environment has different impacts on commuting mode choice due to heterogeneity of individual socio-economic characteristics. The policy implication of the research results is that commuting mode could be optimized by improving land use planning and transit environment designing.

Widely influenced by "violence and terrorism" activities that are organized by the terrorist organization "the East Turkistan Movement" in China, the imaginative geography of Xinjiang has recently changed a lot. As "the East Turkistan Movement" tries to secede Xinjiang away from China by carrying out "violence and terrorism" activities in and out of Xinjiang, the geographical imagination of Xinjiang is gradually changing from a place of beauty and romance into a space of terror and danger. This article focuses on the variation of the geographical imagination of Xinjiang by exploring how Chinese internet media have impact upon it, and discusses how such variation gets involved into Chinese government's policy of anti-terrorism by employing the theory of critical (popular) geopolitics. To this regard, this article pays attention to how Chinese internet media, such as Baidu News, 360 News, Sougou News, and Sina Weibo, produce, practice, negotiate, and reproduce the geographical meanings of the place and space of Xinjiang, by drawing on the textual analysis and online anthropological exploration of the discursive practice of abovementioned internet media and audiences' responses to them. In doing so, this article summarizes the empirical studies in this body of research. It can be concluded that, the internet media produces the negative geographical knowledge of Xinjiang by representing and spreading the information of "violence and terrorism" activities in and out of Xinjiang, and thereby constructing the negative geographical imagination of Xinjiang. Furthermore, such imagination is incessantly negotiated and reproduced in the process of media consuming by audiences. The negotiation and the reproduction of the geographical meanings of Xinjiang positively get involved into and keep in consistence with Chinese government's policy of anti-terrorism, thus the critical (popular) geopolitics model of Chinese anti-terrorism is constructed in the end of this article. Finally, this article could be widely read as a contribution to: (1) human geography, which gets engaged in the discussion of people's everyday life in producing geographical meanings into geography studies; (2) geopolitics, which subverts the paradigm of traditional geopolitical studies that focuses on the influence of the ontological and objective geography upon statecraft practices, and turns to viewing the imaginative geography as an important research object in geopolitical studies; (3) governance, by which the study of internet media is valuable and meaningful for government's guidance of the discourse of mass media.