Transport and mobility result in a range of costs and benefits. Some of these are felt directly by transport users: the costs of petrol or a rail ticket, or the benefit of getting to work conveniently by car or train. By paying for fuel or a ticket, transport users assume a share of the costs that they cause. There are other costs, however. Although these are caused by mobility, they are not reflected in its price. These are known as external costs, and they are environmental and accident and health-related in nature. These costs are borne by third parties, by the general public, or by future generations.