The Quality Bus Partnership has committed to publish a monthly measure of bus service punctuality in the York area.
The published measure is calculated using timings from every bus service in the York area for which real-time information is available. This currently comprises all local bus services operated by Arriva, EYMS, First and Transdev (excluding CitySightseeing).
The measure provides a picture of overall punctuality across all routes in York over the last 12 months.
For every journey on each bus service, the schedule deviation (the difference between the timetabled departure time and actual departure time) is recorded at each timing point (a stop where buses are required to wait until the timetabled departure time if they arrive early).
An average of all the recorded times is then calculated, 5 times per day, for the following time periods:
- Morning (00:00 - 06:59)
- AM Peak (07:00 - 09:29)
- Intermediate (09:30 - 14:59)
- PM Peak (15:00 - 17:59)
- Evening (18:00 - 23:59)
The reported punctuality figure for each month consists of the percentage of measure periods during that month where punctuality is:
- Good - average schedule deviation less than 4 minutes.
- Outstanding - average schedule deviation less than 2 minutes.
To produce a comparable measure, from time to time where exceptional traffic delays occur as a result of circumstances outside the bus operators' control, the punctuality data for that day will be declared void and discounted from the calculation.
Void days might occur as a result of:
- Very busy events attracting large crowds and potentially involving road closures, eg. York Races, Yorkshire Marathon;
- A serious incident in the city centre or on key arterial roads- eg. a major road traffic accident;
- Severe flooding requiring significant bus route diversions.