Combining “Ride-Alongs” and Wearable Sensors to Study Perceptions and Exposure En Route

Abstract

Background: Active mobility is specifically beneficial for health and wellbeing of urban dwellers. However, while people actively move around in urban traffic, they are exposed to urban stressors such as air pollution and noise, which adversely impact health and wellbeing. Traditionally, exposure research is based on objective measurements or model simulations. The subjective experience of exposure is rarely considered and typically assessed by post-hoc questionnaires, thus, neglecting the momentary environmental stimuli experienced in traffic. This study addresses this research gap by exploring experiences and health perceptions while walking/cycling. The aim is to examine en route experiences and perceived exposure, reveal in-situ actions and discover cyclists’/pedestrians’ avoidance strategies to reduce health risks and improve wellbeing. Methods: We developed a novel mixed methods approach: (1) Go-/Ride-alongs with 28 participants in Berlin, Germany, were conducted. We accompanied participants on their daily way from work to home, applied a semi-structured questionnaire while cycling/walking and discovered participants’ experiences, actions and perceptions on-site. (2) Simultaneously, noise (dB(A)), GPS and air pollution (particle number concentrations of PM 0.5-2.5µm) were registered with wearable sensors and situations captured photographically. Using qualitative GIS approaches, we combined the objective exposure data with subjective perceptions. Results: The measured exposure was not always in line with the perceived exposure. We explored the reasons for these differences by accompanying the interviewees. Situations with high noise or air pollution levels were sometimes evaluated as comfortable due to visual experiences en route (e.g. greenery, water, urban aesthetics, entertainment) or positive attitudes (e.g. close to home, end of work, memories). High sound levels cannot always be interpreted as noise: e.g. musicians in the subway or birds/leaves in parks are perceived positively, even though the measured noise may be high. Streets with high traffic volume lead to perceived noise and air pollution, anger and distress – being in line with measurements. We also revealed the importance of “hidden paths” to avoid exposure and actions to decrease exposure impacts (e.g. increase distance to emitters at traffic lights). Emotions (e.g. anger, resignation, irritation) were articulated when experiencing exposure. Conclusions: Our results indicate the importance of on-site perceptions. Therefore, future studies of cyclists/pedestrians should consider exposure, health perceptions and experiences jointly. For addressing the complex interrelation of active mobility and health, mobile methods such as Go-/Ride-Alongs or participatory mapping approaches can be beneficial and should receive greater attention in transport planning for healthier mobility.