Road traffic counts
Britain's road traffic counts in Python: annual average daily flows at 46,754 count points, how they are estimated, trends, hourly profiles, vehicle-kilometres, cycling, lorries and collision rates.
The Department for Transport publishes a traffic figure for every road it counts in Great Britain: an annual average daily flow, by vehicle type, for 46,754 count points from 2000 to 2025, and the hourly counts behind them. It is the most detailed open record of where a country drives. It is also mostly projection: a manual count on one weekday, expanded to a year and carried forward until the next count, so only 38.6% of its values are a measurement at that point in that year.
The guides here read the file, explain how an AADF is made, build trends from the points that were actually counted, and turn flows into vehicle-kilometres, hourly profiles, cycling and lorry maps and collision rates. Two pages deal with the traps: a median that falls whenever the survey adds minor roads, and estimated values that all grow by the same percentage.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Read UK Road Traffic Counts in Python
- How to Measure Traffic Trends from Count Points That Were Actually Counted
- How to Build Hour-of-Day Traffic Profiles from Manual Counts
- How to Turn Traffic Counts into Vehicle-Kilometres by Region
- How to Measure Cycling from Road Traffic Counts
- How to Map Lorry Traffic and Freight Corridors from Count Points
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
Related topics
Subjects that keep coming up alongside this one, most overlap first.