Potential accessibility to the workplace by public transit and its social distribution in Lille, France: A scenario-based equity appraisal

In this paper, we appraise the social equity of urban mobility policy following Levinson and Krizek's (2018) and Zelinski's (1971) principles of "mobility revolution" and "time geography" and building on recommendations from the European Consortium on Transport Equity analysis (TEA COST Action, 2012). From the database of professional trips made within the 85 municipalities of Lille metropole in 2016, we calculate and set the potential accessibility to the workplace by public transport (PT) at the municipal level, as the ‘good to redistribute'. This allows us to identify the municipalities the most lagging behind, based on the household motorisation rate as well as the potential jobs reachable via the PT system. Then, starting from general observations on sociodemographic differences among commuters to access the job market, we aggregate this indicator at the scale of commuter groups – by gender, household structure, educational background, socio-professional category, and immigration status, defining the ‘members of the society'. Lastly, to test our results and in consultation with local transport authorities, we simulate a reduction of the PT commuting times from the least served municipalities of 10% and then 25%. We analyse the effects of our scenarios on the number and value of the accessible jobs gained, per commuter group, as well as considering different subsets of the municipalities (targeting those with low levels of car ownership). Interpreting results in the light of our decision rule, an extension of the Sufficiency approach, we conclude that transport-oriented policy alone is not the panacea to address social equity and that cross-sectoral solutions are needed, particularly when considering impedance factors and car dependent households.