Buses performance data

Measuring performance

We measure network performance by comparing the number of kilometres a route has done in the last quarter.

We compare each quarter to the same quarter of the previous year, rather than the last quarter of the same year. This is because factors affecting performance, like traffic conditions, can vary depending on the time of year, so this system makes it possible to identify underlying trends.

Scheduled kilometres may not be met because journeys are cancelled or suspended due to:

  • Traffic congestion
  • Staff availability
  • Engineering problems or mechanical breakdown

Quality of service indicators (QSI) are used to monitor service reliability.

Customer satisfaction

We ask a sample of passengers to give a score out of 100 on a wide range of bus service features, based on the journey they have just made. Passengers are carefully selected each quarter to represent all bus passengers in London.

Recent figures can be found in the latest quarter summary document below.

Defining the passenger journey

A passenger journey is defined as one ride on a single vehicle - not a bus trip from A to B as this may include more than one bus ride.

Statistics include all London Buses' contracted services but exclude any non-scheduled kilometres, London Service Permit routes and other special services.

Bus speeds reports

We monitor the speeds of buses to understand the impacts of changing road network conditions. Bus speeds include time spent stationary (for example at traffic lights and at bus stops). Bus speeds are available for the entire network, by borough, and by route.

  • All data is in miles per hour
  • All AM data is taken for Mondays to Fridays, School and Non School days, between 07:00 and 10:00
  • At Route level, some routes may be appear twice. This is because a service change happened during a period. A service change may include a change to a route structure, contract or operator

Factors Affecting Performance

Quarter 4 2020/21:   09 January 2021 to 31 March 2021


Performance across all metrics was far removed from the norm as Covid19 restrictions continued to have a significant impact across London for the whole quarter. Performance was better than Q2 as the entire quarter was under various Covid lockdown conditions and very much better than would normally be expected at this time of year.


Bus services had been reduced during Q1 and Q2 but were back to normal levels by the start of Q3 and this was maintained during Q4. The percentage of the service that was operated was higher than Q4 last year. Industrial action at a major bus operator caused significant additional staff losses but these were more than offset by reductions in traffic losses as the whole quarter was under Covid19 lockdown restrictions which saw less vehicles on the roads and far less occurrence of disruptive events. Traffic losses were less than Q3 and less than half that of Q4 last year. The lost kilometres due to mechanical reasons were similar to Q3 but lower than a year ago.


Until 2017/18, average bus speeds had been in consistent decline. The deterioration had been reversing over the previous two years, although speeds remained much slower than in 2014. Overall bus speeds in Q4 were higher than Q3 and significantly higher than a year ago. This was the case in all areas of London, having been boosted by the impacts of reduced traffic levels during the Covid19 lockdown restrictions.


The dual Covid19 impacts of reduced passenger numbers and less traffic disruption continued to have a boosting effect on reliability. Compared with Q4 a year ago, EWT was significantly improved and was better than Q3. Prior to the initial lockdown EWT had been slightly worse than the previous year though in general terms was still achieving some of the best ever results. Before the start of the pandemic inner London EWT had been improving whilst Outer London had recorded a deterioration. Covid restrictions have brought about significant improvements across all areas of London and the gradual return towards more normal levels during Q4 has also been similar across all areas of London. Punctuality of low frequency services also saw a similar boost due to the Covid19 impacts whilst night buses departing on time recorded record performance in Q4.

International Bus Benchmarking Group

London is a member of the International Bus Benchmarking Group (IBBG), an international knowledge sharing network of bus companies. It was established in 2004 and is facilitated by Imperial College London.

Benchmarking is a continuous systematic process for evaluating the products, services, processes or organisations that are recognised as representing best practice for the purpose of organisational improvement. A blend of operational and customer metrics are used to track the performance of the bus network.

Every year, a review of buses performance monitoring is evaluated internally and presented to TfL's Independent Investment Programme Advisory Group (IIPAG) by Imperial College London to justify expenditure and ensure quality of service provided to passengers.