A study led by researchers from the Imperial College London evaluated the effects of daily travel in different transport modes on an objective proxy measure of stress, the galvanic skin response (GSR). The research found that active travel in cities, i.e. walking or biking, reduces stress compared to motorized transportation. Prof. Regine Gerike, head of the Chair of Integrated Transport Planning and Traffic Engineering at the “Friedrich List” Faculty of Transport and Traffic Sciences of TU Dresden, was involved in the project as an author.

Stress is one of many ailments associated with urban living, with daily travel as a potential major source. Active travel, nevertheless, has been associated with lower levels of stress compared to other modes.

GSR sensors ideal for studying stress reactions

As a proxy measure of stress, the galvanic skin response (GSR), a measure of continuous variations in the electrical conductance of skin, was used. The skin conductance is understood to vary with the state of sweat glands in the skin, itself regulated by the Autonomic Nervous System (ANS). The sympathetic branch of ANS influences sweat glands to produce more sweat which in turn increases skin conductivity. Therefore, the measurements of GSR have also been used to indicate psychological or physiological stimulation. GSR measurements can be made continuously, in a way that is non- intrusive and non-disturbing, using wearable sensors, such as the Body Media Sensewear. GSR sensors are thus ideal for the study of stress responses to individuals’ daily routines, such as during travel.

The international team of authors collected data from 122 participants across 3 European cities as part of the Physical Activity through Sustainable Transport Approaches (PASTA) study. The data collected were GSR measured every minute alongside confounders (physical activity, near-body temperature) during three separate weeks covering 3 seasons; sociodemographic and travel information through questionnaires. Causal relationships between travel in different transport modes (the “treatment”) and stress were established by using a propensity score matching (PSM) approach to adjust for potential confounding and estimating linear mixed models (LMM) with individuals as random effects to account for repeated measurements. In three separate analyses, we compared GSR while cycling to not cycling, then walking to not walking, then motorized (public or private) travel to any activity other than motorized travel.

The findings reveal that Cycling reduces GSR by up to 11% compared to other non-cycling activities and Walking reduces GSR by up to 6% compared to other non-walking activities. Motorized travel increases GSR by up to 1% compared to any other activities than motorized travel.

Active mobility offers a welcome way to reduce stress in urban dwellers’ daily lives. Stress can be added to the growing number of evidence-based reasons for promoting active travel in cities.

Study was supported by EU project PASTA – Linking Transport and Health

This work was supported by the European project Physical Activity through Sustainable Transportation Approaches (PASTA). The project aimed to link transport and health by promoting active mobility in cities (i. e. walking, cycling or e-biking, also in combination with the use of public transport) as an innovative way of integrating physical activity into our daily lives.

Prof. Regine Gerike was involved in the PASTA project from the very beginning - from the drafting of the application outline to coordination tasks to content-related work such as the development of a research and survey concept and the implementation of the large empirical survey at the various locations.