A London Underground benchmarking report using CoMET data from 2013 compared operating cost breakdowns and revenues between the Underground and its international peers. CoMET data is in principle anonymized, but it’s not hard to find which city is which, and in particular, whereas London, Paris, and Berlin all spent around $6/car-km on operations in 2013 costs, New York is the city labeled “Am” that spent $10/car-km.

More recently, I followed up on these costs by looking at 2020s data, finding little for Berlin and even less for Paris, but finding exact costs per car-km for New York and per train-km for London. London has seven cars per train, from which we can impute, in 2024 PPP prices, $6.2/car-km in London; New York’s exact costs are $11.58/car-km. BVG’s costs are bundled across modes, but the total costs for 2024 reported in the Lagebericht und Jahresabschluss 2025 are 1.6B€; if U-Bahn costs per car-km and bus costs per bus-km were as in New York and tram costs per tram-km were as in Boston, the two rail modes compared on a per train length basis (thus, a Berlin U-Bahn train of 100 meters is deemed to be six New York City Subway cars), the total would be exactly twice on a PPP basis. If the same comparison were made with an adjustment for bus speed (17.9 km/h here, 11.3 km/h in New York), make it 1.6B€ vs. 2.6B€. Either way, it’s very likely Berlin’s U-Bahn operating costs are in the $6-7/car-km range in 2024 prices.

All of this is remarkable, because prices between 2013 and 2024 rose, by a factor of 1.34 in the US. And yet, despite this inflation, London more or less kept its operating costs unchanged, New York had an increase of slightly less than half the inflation rate, and Berlin likely had a small increase like New York or even smaller.

Moreover, none of the three systems engaged in massive automation over this period, not even the incremental automation of Paris. Furthermore, New York’s subway costs in the short and medium runs tend to rise when ridership decreases and fall when it increases, as fixed costs are spread across more service; the number of employees per unit of service provided rose when ridership fell after WW2 and fell when it recovered. However, the period 2013-24 was not one of major service increases in any of the cities: all three opened new lines, but only short ones, and none of the three embarked on a scheme to massively increase service – London had some increases but New York if anything provides less service now than it did in the early 2010s. Thus, no short-term shock can explain the over-the-decade fall in real operating costs in all three cities.

This contrasts with buses, which are dominated by variable labor costs. In the United States, the cost of running a bus is the wage of the operator plus various overheads, of which the largest is the wage of the maintenance crew. In Europe, bus driver wages are lower, but buses are also cheaper to procure and more fuel-efficient, and overall the system is dominated by wages rising faster than inflation and by variable and not fixed costs.