How late are Britain's buses? 39M arrivals, measured

Most bus operators in Great Britain now publish where their buses are, every few seconds, through the government's Bus Open Data Service. TransCAPI matches each of those positions to the timetabled trip the bus is running, and records when it passed each stop. Do that for every bus that reports, all day, and you can say how punctual buses actually are, not how punctual a timetable says they should be.

Here's what three weeks of that looks like: 39 million stop arrivals from 344 operators on 8,854 lines, between 30 September and 20 October 2026.

The Traffic Commissioners, who regulate bus operators, count a bus as on time if it's no more than 1 minute early and less than 6 minutes late. Early counts against it, because a bus that leaves early can be gone before you reach the stop. I've used the same window, and called a bus very late at 15 minutes or more.

So roughly one bus in four is outside the window, and one in ten is early enough to strand someone who arrived at the stop on time.

By line, the picture is consistent. Of the 3,324 lines with at least 2,000 observations, the median line was on time 75.7% of the time. One line in ten managed 85%. Hardly any reached 95%, the figure usually treated as the benchmark for a punctual service.

Nearly nine buses in ten leave their first stop on time. By the last stop fewer than half are, and more than a third are early. That isn't buses speeding up. It's the timetable: operators pad the final stretch of a route with recovery time, so a bus running late through the middle catches up at the end. It makes a line look better at the terminus than it was for the people who used it on the way.

On-time rate by hour of day, outside London:

The early morning is best: at 05:00, 86% of buses are on time and almost none are very late. The morning peak takes it to 70% at 08:00. Then it recovers through the late morning before the afternoon is the worst stretch of the day: 65% on time at 16:00, with 6.7% of buses 15 minutes or more late, thirteen times the early-morning rate. The slide starts at 15:00, when schools finish, not at 17:00 when offices do.

Late in the evening the problem flips. At 23:00 only 1% of buses are very late but 17% are early: empty roads, and drivers with nobody to wait for.

Monday is the best weekday, and it gets a little worse through the week. The worst single day in the three weeks was Friday 16 October (70.9%). The best was Sunday 4 October (78.7%).

Every area with at least 200,000 observations in the three weeks, ordered by on-time rate. Areas are the ones the national stop database uses: counties, metropolitan areas and some cities on their own.

The spread is 14 points, from 80% in Wiltshire and Plymouth to 66% in Oxfordshire, which also has the most very late buses (4.8%). The North East does well: County Durham and Tyne and Wear are both above 78%. The big metropolitan areas sit close together in the middle, between 72% and 75%. Some areas have a timing problem in the other direction: in Cumbria 15% of buses are early, and in Devon 14%.

Read this as how buses run in a place, not as a league table of operators. An area's figure mixes many operators, its traffic, and how its routes are timetabled; a congested city and a rural county aren't the same job.

No single area in Wales or Scotland reaches the threshold, so here they are as nations. Wales: 77.0% on time, 11.6% early, 1.9% very late, from 640,000 arrivals. Scotland: 79.7%, 7.3% and 1.8%, from 150,000. Few Scottish buses report positions to the national service yet, so treat Scotland's figure as a sample.

Including London, the on-time figure drops to 70.5% and "early" jumps to 13%. In London on its own, 23% of arrivals are more than a minute early. That doesn't mean London's buses are badly run. Most London routes are high-frequency: the timetable is a bus every few minutes, and TfL manages them on the gaps between buses, not on clock times. Measuring them against a timetable produces numbers that mean little, so the figures above leave London out. The same goes, to a lesser degree, for frequent urban routes elsewhere, which is one reason a single national figure should be read with care.

All of this is in the API, by line, stop and hour, over the last 7 to 56 days:

GET /v1/bus/reliability.json?operator=<code>&line=<line> GET /v1/bus/stop_reliability/<atcocode>.json

The first gives a line's on-time, early, late and very-late shares, its mean delay and the same by hour. The second gives each line's punctuality at a single stop, with the median and 90th-percentile delay: the "how early do I need to leave" number. Journey results use the same history to give the chance of making each change. The punctuality guide has runnable Python.

Try it. TransCAPI is one API for buses, trains and journey planning across Great Britain. A free key gives you 500 requests a day with no card; the journey docs cover the parameters.