The external costs of private versus public road transport in the Metropolitan Area of Santiago, Chile

At peak times, marginal external costs per kilometer for petrol cars, diesel cars and buses are estimated at USD 0.51, USD 0.53 and USD 1.80 respectively. When these values are converted to passenger-kilometer, petrol cars, diesel cars and buses impose a marginal external cost of USD 0.41, USD 0.42 and USD 0.04 respectively. At off-peak times, all these values are reduced as congestion decreases significantly. The marginal external cost for petrol cars, diesel cars and buses are USD 0.15, USD 0.16 and USD 0.78 respectively. Differences in marginal external costs per passenger-kilometer between cars and buses shrink as these costs fall to USD 0.12, USD 0.13 and USD 0.05 for petrol car, diesel car and bus respectively.