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Bus route 331

Transport
331
Usually an Alexander Dennis Adl Enviro 200.

66% on timeof departures in the week ending 17 October 2026, leaving no more than 2.5 minutes early or 5 minutes late. Half of London's timetabled routes managed 73% or better.

The last week, day by day
Share of departures leaving on time.

Watch a day of route 331’s buses: every bus, replayed on the map. Or click a day on the chart.

The weekly figures

The share of departures that left on time.

Week endingRuislip StationUxbridge Station
21 Jun 2025no datano data
28 Jun 202587%80%
5 Jul 202592% thin63% thin
12 Jul 202586% thin48% thin
19 Jul 202578%52%
26 Jul 202569%57%
2 Aug 202579%57%
9 Aug 202591%53%
16 Aug 202586%67%
23 Aug 202582%59%
30 Aug 202588%64%
6 Sept 202584%72%
13 Sept 202580%57%
20 Sept 202581%46%
27 Sept 202584%56%
4 Oct 202581%48%
11 Oct 202584%62%
18 Oct 202589%54%
25 Oct 202595%68%
1 Nov 202581%73%
8 Nov 202588%61%
15 Nov 202580% thin64% thin
22 Nov 202588% thin64% thin
29 Nov 202573%74%
6 Dec 202581%80%
13 Dec 202573%54%
20 Dec 202572%68%
27 Dec 202577% thin61% thin
3 Jan 202691%78%
10 Jan 202694%70%
17 Jan 202694%80%
24 Jan 202681%67%
31 Jan 202677%59%
7 Feb 202682%63%
14 Feb 202681%67%
21 Feb 2026no datano data
28 Feb 2026no datano data
7 Mar 202694%60%
14 Mar 202667%52%
21 Mar 202672%55%
28 Mar 202683%63%
4 Apr 202686%73%
11 Apr 202691%59%
18 Apr 202688%67%
25 Apr 202678% thin59% thin
2 May 202659%37%
9 May 202666%48%
16 May 202693%68%
23 May 202680%63%
30 May 202685%62%
6 Jun 202680%54%
13 Jun 202689%60%
20 Jun 202677%48%
27 Jun 202680%51%
4 Jul 2026no datano data
11 Jul 202682%51%
18 Jul 202690%45%
25 Jul 202664%61%
1 Aug 2026no datano data
8 Aug 2026no datano data
15 Aug 2026no datano data
22 Aug 2026no datano data
29 Aug 2026no datano data
5 Sept 202683%56%
12 Sept 202684%58%
19 Sept 202681%72%
26 Sept 202680%43%
3 Oct 202680%46%
10 Oct 202675%37%
17 Oct 202663%69%

A passenger going by the timetable at Ruislip Station would find about four departures in ten leaving more than 2.5 minutes early or 5 minutes late.

Ruislip Station
On time
63%
Cut short
1.0%
Uxbridge Station
On time
69%
Cut short
0.0%

70 minutes was the longest gap between buses this week, at Oakside towards Belmont Road, on Wednesday 14 October from 19:44 to 20:54. This excludes any gaps caused by holes in our own data. Watch it happen →

Journeys cut short

Last week: 1.5% of journeys were turned back before the end of the line in the week ending 17 October 2026. Everyone on board has to get off; for anyone waiting further along the route it's effectively a cancellation.

towards Ruislip Station

Last week, 4 of 277 journeys (1%) were turned short.

  • Reservoir Road3.2 km short of the end 2
  • Jackets Lane5.2 km short of the end 1
  • Mount Vernon Hospital9.5 km short of the end 1

towards Belmont Road

Last week, 4 of 274 journeys (1%) were turned short.

  • Savay Lane4.9 km short of the end 1
  • Northwood Station14.2 km short of the end 1
  • The Harefield Academy8.9 km short of the end 1
  • St Mary's Road7.1 km short of the end 1

Each place is the last stop the bus was timed at before it turned round, with the typical distance it fell short of the end of the line. The five busiest are named; the rest are counted together.

Compared with TfL's own figures

QuarterTfLOurs
2025/26 Q313 Sept – 2 Jan 202685% on timeno figure
2026/27 Q11 Apr – 26 Jun 202683% on timeno figure

TfL's figures come from its own tracking equipment and its own timetable; mine are computed from the buses' public position feed. They are the same calculation on independent data, so they should broadly agree and move together rather than match exactly.

About this data
Data collected, week ending 17 October 2026
100% of the week. This is the share of the week for which we hold bus location data at all, across the whole of London rather than for this route. A week under 60% is not published; under 90% it is marked as thin.
Departures observed
  • Ruislip Station: 200 departures seen
  • Uxbridge Station: 197 departures seen
A guide to how much evidence sits behind this week's figures, not a measure of the service.
How it is measured
Every day, 05:00–23:59. On time means leaving no more than 2.5 minutes early or 5 minutes late. A day with less than four hours of data collected shows no daily figure. How these figures are made.
Gaps in the record for this period (39)

Most recent first. Hover a week on the chart and it will name the gap behind it. Most are a few missing hours on an otherwise ordinary day.

  • 17 Sept 2026 partial day, no data 12:00-12:59: our collector was down (machine off or power cut)
  • 28 Aug 2026 partial day, no data 20:00-23:59: our collector was down (machine off or power cut)
  • 29 Jul – 26 Aug 2026 no collection: the volunteer BODS archive was down and our own collector had not yet started
  • 28 Jul 2026 partial day, no data 11:00-23:59: no collection: the volunteer BODS archive was down and our own collector had not yet started
  • 7 Jul 2026 partial day, no data 15:00-15:59: gap in the volunteer BODS archive (its collector was down)
  • 5 Jul 2026 partial day, no data 06:00-11:59: gap in the volunteer BODS archive (its collector was down)
  • 4 Jul 2026 partial day, no data 06:00-21:59: gap in the volunteer BODS archive (its collector was down)
  • 2 Jul – 3 Jul 2026 gap in the volunteer BODS archive (its collector was down)
  • 8 Jun 2026 partial day, no data 07:00-08:59: gap in the volunteer BODS archive (its collector was down)
  • 7 Jun 2026 partial day, no data 12:00-12:59, 18:00-19:59: gap in the volunteer BODS archive (its collector was down)
  • 6 Jun 2026 partial day, no data 12:00-12:59, 16:00-16:59, 18:00-18:59: gap in the volunteer BODS archive (its collector was down)
  • 27 Apr 2026 partial day, no data 12:00-12:59: gap in the volunteer BODS archive (its collector was down)
  • 21 Apr 2026 partial day, no data 06:00-11:59: gap in the volunteer BODS archive (its collector was down)
  • 20 Apr 2026 partial day, no data 15:00-23:59: gap in the volunteer BODS archive (its collector was down)
  • 16 Apr 2026 partial day, no data 12:00-15:59: gap in the volunteer BODS archive (its collector was down)
  • 28 Feb 2026 partial day, no data 06:00-18:59: gap in the volunteer BODS archive (its collector was down)
  • 16 Feb – 27 Feb 2026 gap in the volunteer BODS archive (its collector was down)
  • 15 Feb 2026 partial day, no data 16:00-23:59: gap in the volunteer BODS archive (its collector was down)
  • 30 Jan 2026 partial day, no data 20:00-23:59: gap in the volunteer BODS archive (its collector was down)
  • 25 Dec 2025 no bus service on Christmas Day
  • 23 Dec 2025 partial day, no data 06:00-07:59: gap in the volunteer BODS archive (its collector was down)
  • 5 Dec 2025 partial day, no data 06:00-08:59: gap in the volunteer BODS archive (its collector was down)
  • 24 Nov 2025 partial day, no data 17:00-17:59: gap in the volunteer BODS archive (its collector was down)
  • 17 Nov 2025 partial day, no data 06:00-09:59: gap in the volunteer BODS archive (its collector was down)
  • 15 Nov – 16 Nov 2025 no London vehicles in the national feed — TfL's export to BODS was down (the volunteer archive itself was collecting)
  • 14 Nov 2025 partial day, no data 06:00-07:59, 13:00-23:59: gap in the volunteer BODS archive (its collector was down)
  • 31 Oct 2025 partial day, no data 06:00-07:59: gap in the volunteer BODS archive (its collector was down)
  • 17 Oct 2025 partial day, no data 06:00-07:59: gap in the volunteer BODS archive (its collector was down)
  • 10 Oct 2025 partial day, no data 06:00-08:59: gap in the volunteer BODS archive (its collector was down)
  • 3 Oct 2025 partial day, no data 06:00-11:59: gap in the volunteer BODS archive (its collector was down)
  • 19 Sept 2025 partial day, no data 06:00-08:59: gap in the volunteer BODS archive (its collector was down)
  • 5 Sept 2025 partial day, no data 06:00-09:59: gap in the volunteer BODS archive (its collector was down)
  • 1 Aug 2025 partial day, no data 06:00-09:59: gap in the volunteer BODS archive (its collector was down)
  • 18 Jul 2025 partial day, no data 06:00-09:59: gap in the volunteer BODS archive (its collector was down)
  • 8 Jul 2025 partial day, no data 06:00-08:59: gap in the volunteer BODS archive (its collector was down)
  • 6 Jul – 7 Jul 2025 gap in the volunteer BODS archive (its collector was down)
  • 5 Jul 2025 partial day, no data 18:00-23:59: gap in the volunteer BODS archive (its collector was down)
  • 4 Jul 2025 partial day, no data 06:00-14:59: gap in the volunteer BODS archive (its collector was down)
  • 25 Jun 2025 partial day, no data 06:00-11:59: gap in the volunteer BODS archive (its collector was down)

For latest timetable and route information, see TfL's official page.

Contains public sector information licensed under the Open Government Licence v3.0; bus data via the DfT Bus Open Data Service and Transport for London. Figures are computed from observed bus positions, every day, 05:00–23:59. How these figures are made. Bus positions from the Department for Transport’s Bus Open Data Service (BODS); the Department for Transport cannot warrant the accuracy or quality of the data published there. Positions before September 2026 come from the Bus Open Data archive generously built and kept by Open Innovations, with thanks. Route lines and stops: Powered by TfL Open Data. Contains OS data © Crown copyright and database rights 2016. Geomni UK Map data © and database rights [2019]. These pages and the bus replay are built independently from open data: Transport for London, the Department for Transport and the bus operators had no part in making them, and none of them endorses them. Not for planning a journey.