In-vehicle crowding on public transportation is a serious problem that transportation planners must address. Recent studies have emphasized that in-vehicle crowding impacts travelers’ stress and health, while other studies have investigated how daily travel affects subjective well-being (SWB). Based on the findings of these studies, we provide useful insights into the value of a reduction in crowding in terms of SWB. The other factor we should consider is adaptation, as the effects of travel discomfort disappear after travelers become accustomed to them. In this paper, we analyzed the direct and stress-related indirect effects of dissatisfaction with in-vehicle crowding on life satisfaction, focusing on whether these effects differ by the length of time commuters have been using trains. Using a sample of 8296 train commuters in Tokyo, we found that (1) dissatisfaction with in-vehicle crowding directly lowers life satisfaction among some groups of short-term train commuters and (2) dissatisfaction with in-vehicle crowding indirectly lowers life satisfaction through stress and health, regardless of whether commuters have used trains for more or less than one year. These results revealed the importance of focusing on the stress-related indirect effects of dissatisfaction with crowding, while direct effects on SWB exist only among some commuters. Our results demonstrated the possibility of adaptation to direct effects.

中文翻译：

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通勤者能适应火车上的车内拥挤吗？

公共交通的车内拥挤是交通规划者必须解决的一个严重问题。最近的研究强调，车内拥挤会影响旅行者的压力和健康，而其他研究则调查了日常旅行如何影响主观幸福感 (SWB)。根据这些研究的结果，我们就 SWB 方面减少拥挤的价值提供了有用的见解。我们应该考虑的另一个因素是适应，因为旅行不适的影响会在旅行者习惯后消失。在本文中，我们分析了对车内拥挤的不满对生活满意度的直接和压力相关的间接影响，重点关注这些影响是否因通勤者乘坐火车的时间长短而不同。使用东京 8296 名火车通勤者的样本，我们发现（1）对车内拥挤的不满直接降低了一些短期火车通勤者的生活满意度；（2）对车内拥挤的不满通过压力和健康间接降低了生活满意度，无论通勤者是否使用过训练超过或少于一年。这些结果揭示了关注与压力相关的对拥挤不满的间接影响的重要性，而对 SWB 的直接影响只存在于一些通勤者中。我们的结果证明了适应直接影响的可能性。无论通勤者使用火车的时间是否超过或少于一年。这些结果揭示了关注与压力相关的对拥挤不满的间接影响的重要性，而对 SWB 的直接影响只存在于一些通勤者中。我们的结果证明了适应直接影响的可能性。无论通勤者使用火车的时间是否超过或少于一年。这些结果揭示了关注与压力相关的对拥挤不满的间接影响的重要性，而对 SWB 的直接影响只存在于一些通勤者中。我们的结果证明了适应直接影响的可能性。