Predict the expected collision reduction from a road safety intervention, corridor by corridor, grounded in a proprietary dataset of measured scheme outcomes from across the UK road network. Demonstrated here for 30 to 20 mph speed limit changes, the approach can be extended to other intervention types where evidence is available.
Each road segment shown is a 30 mph road in Stockton-on-Tees. This map shows the expected percentage improvement in collision risk and the expected absolute collision reduction road given speed limit reduction.
Darker colours represent greater predicted benefit. Segments can be clicked to view their estimated reduction, recorded collision history and key road characteristics.
Predictions draw on a combination of road geometry, traffic volume, calculated road features and wider network context. The model is trained on evidence from 20 mph zone implementations across the UK, including analysis of collision outcomes before and after speed limit changes on comparable roads.
Outputs include corridor-level collision reduction estimates, confidence intervals, and total avoidable collisions per year to support business case development.