
In relation to individual motorised car use, the shift to electric models is only part of the answer, i. e. we still want to see a reduction of the total number of vehicles in our cities. In relation to taxis, the potential for modal shift is much smaller, and they have an important role in the current spectrum of travel options: they are used disproportionately by individuals without access to a private car (most of whom are on low incomes), and they can be essential to people with disabilities and the elderly.
Tackling the pollution factor (NOx and PM) would be an obvious and easy way of improving their environmental impact. If bus companies can be incentivised to make the shift from diesel to low or zero-emissions technology, so can taxi companies.