Compared to other popular modes of passenger transportation, especially buses or trains, the car has a relatively high cost per passenger-distance travelled. Motorists in the United Kingdom seem to spend on the car an average of roughly 1/3 of their average net income, while motorists in Portugal seem to spend 1/2 of their net income. For the average car owner, depreciation constitutes about half the cost of running a car, nevertheless the typical motorist underestimates this fixed cost by big margin, or even ignores it altogether.