Road-crash GNN gains vanish against matched history baselines
An independent reconstruction found no statistically significant advantage for its crash-prediction model over a parameter-free baseline that ranks road segments by past crash counts, putting reported GNN gains under scrutiny in safety-critical work. Across three London boroughs, the model scored 0.90 points below the matched baseline (p=0.61), while the reference architecture lost in all 18 held-out windows. Changing only the baseline’s lookback horizon produced 22.71% to 83.94% accuracy, enough to match every published figure.