## 2 Consequence of Not Using Crowd Management Measures at the PTI
### Reduced Integration Between Modes: Use of Bicycles Inside the Train  
The integration of bicycles with public transport has gained increasing attention in academic research and policy [41, 42]. Previous studies have identified the importance of seamless intermodal connectivity, highlighting the benefits of bike-and-ride systems for reducing car dependency and improving sustainability [43]. However, real-world implementation often faces challenges related to infrastructure, vehicle design, passenger comfort, and operational safety [44, 45].  
Crowding inside train carriages is a major obstacle for multimodal integration. Research shows that interior layout and vehicle density influence passenger satisfaction, accessibility, and boarding/alighting performance [4, 46]. More specifically, the presence of bicycles can generate spatial conflicts with standing passengers and disrupt flow, especially during peak hours [47]. However, empirical data on these interactions remain scarce, particularly in the Latin American context.  
The experimental study conducted by [PERSON] et al. [48] evaluated the operational effects of permitting bicycles inside metro train carriages by observing the interaction between cyclists and passengers under controlled conditions. Using a full-scale mock-up of the Valparaiso Metro train, the research team tested multiple bicycle locations (Zone 1 near the door, Zone 2 between the door and the vestibule, and Zone 3 within the vestibule) and monitored how each affected boarding and alighting flows. The results showed that placing bicycles in the vestibule (Zone 3) minimized interference with passenger movement, as it avoided the key boarding corridor. In contrast, bicycle placement near the door (Zone 1) created significant conflicts and increased dwell time. The study found that passengers altered their paths and behaviors depending on bicycle positioning. When bicycles were located in Zones 1 or 2, passengers displayed hesitation, delayed entry, and spatial reorientation to avoid collisions, leading to increased interaction zones and longer service times. By contrast, bicycles in Zone 3 facilitated better use of space and reduced disruptions, even during high boarding volumes. The authors recommend implementing visual markings and designated bike-holding zones within vestibule areas to formalize this behavior and reduce uncertainty. These findings align with the prior literature indicating that predictable spatial allocation reduces crowding stress [12, 15]. Importantly, participants expressed higher satisfaction and safety perception when bicycles were positioned away from door zones, suggesting that well-integrated bicycle policies can improve the overall user experience. The authors argue that if bicycles are to be permitted onboard, especially in low-occupancy periods, careful planning of train interiors is essential to minimize friction between users. While further study is needed--particularly involving passengers with reduced mobility and during real service conditions--this pilot experiment offers concrete recommendations to support sustainable, multimodal public transport systems in Chile and beyond.