Driving single-occupancy vehicles contributes the largest to CO2 emission, fossil fuel dependency, fatal accidents, and overall air pollution. The first way to discourage it is to designate more dedicated bus lanes, HOV lanes, and bike lanes. Secondly, narrowing our roads would make people realise that they need to get out of congestion and start walking/cycling/taking transit. Thirdly, increase parking fees and reducing parking spaces would also greatly decrease people's willingness to drive.