Under the agreement, wholesale fuel companies would be required to purchase pollution allowances at auction. The sale of those allowances could generate billions for states to invest in carbon-reducing transportation options — like electric buses, electric car charging stations, bike lanes and sidewalks. Supporters say the pact would be a major step toward reducing transportation pollution — while also generating money to help pave the way to a renewable energy future. They estimate the agreement could result in fewer cases of asthma, premature deaths and traffic-related injuries. They also said the shift away from polluting fuels could save hundreds of millions by avoiding the worst impacts of climate change.