Health Impacts of Active Transportation in Europe

Policies that stimulate active transportation (walking and bicycling) have been related to heath benefits. This study aims to assess the potential health risks and benefits of promoting active transportation for commuting populations (age groups 16–64) in six European cities. We conducted a health impact assessment using two scenarios: increased cycling and increased walking. The primary outcome measure was all-cause mortality related to changes in physical activity level, exposure to fine particulate matter air pollution with a diameter <2.5 μm, as well as traffic fatalities in the cities of Barcelona, Basel, Copenhagen, Paris, Prague, and Warsaw. All scenarios produced health benefits in the six cities. An increase in bicycle trips to 35% of all trips (as in Copenhagen) produced the highest benefits among the different scenarios analysed in Warsaw 113 (76–163) annual deaths avoided, Prague 61 (29–104), Barcelona 37 (24–56), Paris 37 (18–64) and Basel 5 (3–9). An increase in walking trips to 50% of all trips (as in Paris) resulted in 19 (3–42) deaths avoided annually in Warsaw, 11(3–21) in Prague, 6 (4–9) in Basel, 3 (2–6) in Copenhagen and 3 (2–4) in Barcelona. The scenarios would also reduce carbon dioxide emissions in the six cities by 1,139 to 26,423 (metric tonnes per year). Policies to promote active transportation may produce health benefits, but these depend of the existing characteristics of the cities. Increased collaboration between health practitioners, transport specialists and urban planners will help to introduce the health perspective in transport policies and promote active transportation.

Scenarios were built based on assumptions about the modal distribution and shifting between modes of transport, focused on increasing active transport assumed that most of the trips would be substitutes from public transport.

Input data.
All the transport data included in the analysis come from official records or transport surveys from each city. This data may have been collected using different methods but are the best available data. However we acknowledge that there is some uncertainty in the data and that the data may have been more reliable had it been collected using the same methodology, with preferably objective assessment methods such as automatic counters and automatic tracking of individuals The health impacts of increased physical activity by active transport taking into account baseline levels of physical activity (METs/H/w) in each city by age group and sex, which we obtained from local and national records and surveys. The baseline levels of physical activity used by the model in each city are presented in the tables 3 to 8 in METs/h/w.

Public transport trips
Public transport trips included metro, train, bus, and tram trips, depending on the city.
Was assumed that public transport trips involved 10 minutes of walking and was included in the model the benefits of physical activity, the risk of suffering a road traffic fatality as a pedestrian and the inhalation of air pollution during the 10 minutes walking in the risk associated with public transport.

Carbon dioxide.
Scenario A: 35% of all trips by bicycle; Scenario B: 50% of all trips walking. Negative numbers (-) mean avoided deaths; Positive numbers mean increased deaths.
Scenario A: 35% of all trips by bicycle; Scenario B: 50% of all trips walking. Negative numbers (-) mean avoided deaths; Positive numbers mean increased deaths.        This graph shows a reduction in the fatal accidents per million of travellers (cyclist or pedestrians) when the number of travellers (cyclist or pedestrians) increases in the population. Base on these data from the six cities, a incidence rate ratio (IRR) of fatal accidents was estimated for cyclist or pedestrians. This IRR (for cyclist or pedestrians) was used to quantify the reduction of fatal accidents in the different cities according with the expected increment of travellers (cyclist or pedestrians) in each scenario.  Scenario A: 35% of all trips by bicycle; Scenario B: 50% of all trips walking. The "safety in numbers" approach, was based on the incidence rate ratio of fatal traffic accidents (in cyclists or pedestrians) estimated by the six cities data. Negative numbers (-) mean avoided deaths; Positive numbers mean increased deaths. CI: Confidence intervals. Scenario A: 35% of all trips by bicycle; Scenario B: 50% of all trips walking. The "safety in numbers" approach, was based on the incidence rate ratio of fatal traffic accidents (in cyclists or pedestrians) estimated by the six cities data.     This sensitivity analysis considered that traffic is the most important source of air pollution in the cities and assumed that traffic sources have a fivefold higher toxicity for air pollution, as suggested by previous authors (7;8). For cities like Prague, Warsaw and Paris, which have the highest concentrations of air pollution of the six cities, this fivefold toxicity factor produced small net harms rather than benefits in scenarios A (for Paris and Prague) and B (in Prague and Warsaw). For scenario A (in Paris and Prague) this is due to the high concentrations of air pollution in both cities and the substitution by cycling trips that implies higher inhalation rates in travellers compared with other modes of transport. For scenario B (in Prague and Warsaw) this is due to the combination of the high traffic fatality rates and high concentrations of air pollution in both cities.