In a report from the FFU, Rafael Postpischil and Klaus Jacob from the FFU, together with scientists from Fraunhofer FIT, evaluate the state of research analyzing both environmental and distributional impacts in the transport sector.   

In the approximately 300 studies identified, the environmental and health impacts of the current transport system are highlighted as tending to be unequally distributed across the population. In particular, the burden of traffic-induced air pollutants and noise emissions is said to be more pronounced for people with low incomes, less education, and migration histories. 

The findings on distributional effects of currently used transport and environmental policy instruments were also evaluated. The conclusion is mixed: For some transport policy instruments, there are findings on both negative environmental effects and negative distributional effects (such as company car taxation, fuel taxes or parking fees), while for others positive environmental effects but negative distributional effects are indicated(including purchase premiums for e-cars and plug-in hybrids). However, the promotion of local public transport, walking and cycling, and the CO2 component of the current vehicle tax, for example, score positively in terms of both transport and environmental policy.   

Some transport and environmental policy instruments that feature prominently in the public debate are scarcely examined from a distributional perspective: among them driving bans, bans on certain drive technologies, alternative fuels or emission limits - further research is thus needed here.  

Gaps in the existing research are also evident concerning the considered effects. Among the environmental changes, for example, emissions of greenhouse gases and air pollutants were most frequently considered in terms of environmental and distributional effects, while among the modes of transport, private motorized transport was followed by public transport. Likewise, unequal impacts on gender and ethnicity are rarely examined - unlike income groups or urban-rural differences. 

The current FFU report with the detailed evaluation of the state of research on the topic can be found here.