it seems to me that the right way to solve the regressive nature of pigovian taxes like congestion fees or gas taxes is to implement them with subsidies so that they are largely revenue neutral.
The idea being to give everyone a tax credit equivalent to what they are probably going to spend on usage fees. The incentive structure remains, as they get to keep the money if you aren't contributing to the negative externality, and on average nobody is any worse off than before.
”A Pigovian (Pigouvian) tax is a liquid waste, or effluent, fee which is assessed against private individuals or businesses for engaging in activities that create adverse side effects. Adverse side effects are those costs which are not included as a part of the product's market price.”
"A Pigovian tax (also spelled Pigouvian tax) is a tax on any market activity that generates negative externalities (costs not included in the market price). The tax is intended to correct an undesirable or inefficient market outcome, and does so by being set equal to the social cost of the negative externalities. In the presence of negative externalities, the social cost of a market activity is not covered by the private cost of the activity. In such a case, the market outcome is not efficient and may lead to over-consumption of the product.[1] Often-cited examples of such externalities are environmental pollution, and increased public healthcare costs associated with tobacco and sugary drink consumption."
Basically what many economists are recommending for dealing with climate change, namely a carbon tax + dividend scheme. That is, a (rising) carbon tax sufficient to reduce carbon emissions quickly enough, and proceeds from said tax paid out in equal amounts to each citizen.
The idea being to give everyone a tax credit equivalent to what they are probably going to spend on usage fees. The incentive structure remains, as they get to keep the money if you aren't contributing to the negative externality, and on average nobody is any worse off than before.