Urban Congestion Scaling Discrepancy Worldwide: cities metabolate transportation inefficiency by a ¾ power law

Urban traffic congestion is a hallmark cost of urbanization, yet the phenomenon has rarely been examined at a truly global scale. Here, we leverage hourly traffic congestion data across 359 cities in 55 countries in 2025 to fit urban scaling models, revealing that traffic congestion follows sublinear scaling consistent with Kleiber’s law (β ≈ 0.75) of organismic metabolism. Congestion grows with city size, but more slowly than population, challenging long standing assumptions of super linear diseconomy of scale. The pattern is not uniform in space and time, however. In some countries congestion scales via peak congestion spreading across the day rather than by sharper rush-hour spikes, encouraged by work-from-home and other adaptive behaviour. We also find that metro systems increase the deceleration of congestion with city size. We speculate that as cities adapt to a more even use of their distribution networks over time, their metabolism may function more naturally as a super-organism, determined at the limit, by the physical geometry of the road network. Also consistent with Kleiber’s law is our finding that for smaller cities, the deceleration is nearer to 2/3 than 3/4.