Did the metropolitan public transport subsidy get cars off city streets?

Since September 2022, the Government has made commuter rail passes practically free, in addition to an extra subsidy amounting to discounts of up to 50-60% on metro passes in Spanish cities.

In the 2023 General State Budget, these measures were allocated almost €700M. It is therefore one of the most ambitious policies undertaken in recent years to promote public transport.

The stated objective of the measure was to reduce the use of private vehicles, thereby seeking to align the goals of reducing CO2 emissions and easing the energy price shock (in this case, petrol prices) following the invasion of Ukraine.

To assess whether the measure has served this purpose, we use real-time data on private vehicle traffic in Madrid. With these data we build a traffic series for the city and check whether traffic has fallen significantly since the introduction of the measure. To do so, we use a causal estimation method that compares this actual evolution with a statistical model that draws the same line, but in an alternative world without the measure.

We observe no significant difference. That is: with the available data, it cannot be claimed that the subsidy has reduced the number of cars in Madrid. This effect does not appear either in cumulative terms from 1 September 2022 to 30 June 2023, or in day-to-day averages.

We use the same method to detect any effect in specific groups, areas or periods. We find no effect whatsoever when isolating the sensors on expressways (M-30); on roads into or out of the city; in areas with more or less traffic to begin with; in high-, middle- or low-income areas; or with or without nearby access to public transport stops.

We believe these results call for a rethink of policies to promote public transport. We therefore propose: