Where the accessibility gains of high-speed rail go: air competition and spatial equity on Vietnam's planned North-South corridor - data and code

Data and code supporting an ex-ante assessment of the accessibility gains of the planned North-South high-speed railway of Vietnam (1,541 km, Hanoi to Ho Chi Minh City). The package contains the Python scripts that build a road graph of 1.88 million directed edges from an OpenStreetMap extract of August 2026, assign the WorldPop 2020 population grid to 37 territorial units, and compute door-to-door travel times by road, air (40 non-stop domestic routes) and high-speed rail at 300, 320 and 350 km/h. It also contains the derived travel-time matrices, the potential-accessibility gains and their exact decomposition into internal dominance and external gain, population-weighted inequality indices, a reduced model without a network, the door-to-door exposure of the 40 air routes, and the sensitivity and robustness tests (intrazonal times, several origins per unit, directed travel times, all-stop service, out-of-sample access speed). Every number, table and figure of the article can be reproduced with run_all.sh after downloading the two public source files listed in README.md. Code is released under the MIT licence and data under CC BY 4.0; travel times are produced works derived from OpenStreetMap data (ODbL).