Traffic flow

Our appraisal process for investment decisions includes detailed modelling of our projects' impact on traffic patterns. Key elements of this are forecasts of the number of people affected by the project. This includes people who make changes to their journey due to the project, such as taking a different route.  

This dashboard compares predicted and observed traffic flow to evaluate how accurate these traffic forecasts were. 

Summary

Forecasts were generally accurate, with almost half of evaluations showing observed traffic within 15% of forecasts. 

Some projects were less accurate than this and there's a tendency for actual observed traffic to be lower than forecast.