Pricing in externalities is job 0. I want to go from A to B. Do you want option a) be alone, £100, b) share car, £60, c) most efficient, switch to bus and tra

Pricing in externalities is job 0. I want to go from A to B. Do you want option a) be alone, £100, b) share car, £60, c) most efficient, switch to bus and train, £30