City-State Mobility Revolution: Singapore, Hong Kong, Hamburg, and Dubai (2005–2024) In the bustling city-states of Singapore, Hong Kong, Hamburg, and Dubai, transportation systems have evolved dramatically from 2005 to 2024, shaped by unique policies, urban constraints, and economic ambitions. Singapore’s Certificate of Entitlement (COE) caps car lifespans at 5.55 years and car growth at 50.1%, while its MRT network doubled (+112.1%) and ridership soared (+70.2%). Hong Kong’s high taxes fuel car growth (+60.5%) but maintain a 90% public transport mode share. Hamburg’s mature system sees modest rail (+7.7%) and bus (+36.4%) growth, with a 27% mode share. Dubai’s explosive metro (+∞) and taxi (+250%) growth drives a 320% ridership surge, though cars dominate (+150%). Environmental policies, urban planning, and economic factors shape these trends, with Singapore and Hong Kong prioritizing public transport, Hamburg balancing sustainability, and Dubai transitioning from car-centr...