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 2 2020/21:   27 June to 18 September 2020


Performance across all metrics was far removed from the norm as Covid19 restrictions continued to have a massive impact across London for the whole quarter. Performance was worse than Q1 but still much better than would normally be expected.


Bus services had been reduced at the end of March, but service levels began a recovery towards the end of May and overall 98% of normal mileage was scheduled during Q2. The percentage of this reduced service that was operated was far higher than Q2 last year with a reduction in all lost mileage categories. The percentage lost due to traffic delays was double the Q1 figure but significantly lower than normal for the 2nd quarter as Covid19 restrictions reduced disruption and saw less vehicles on the roads. Despite the impact of Covid19 a bus driver recruitment push saw lower staff losses than a year ago. The occurrence of disruptive events was less than usual but included a series of Black Lives Matter demonstrations in the early part of the quarter and Extinction Rebellion demonstrations in early September. Lost kilometres due to mechanical reasons was lower compared with a year ago as reduced services meant less intensive use of available vehicles.


Until 2017/18, average bus speeds had been in consistent decline. The deterioration had been reversing over the past 2 years, although speeds remained much slower than in 2014. Overall bus speeds in Q2 were significantly higher than a year ago in all areas of London having been boosted by the impacts of Covid19 though were much slower than Q1 as traffic levels began an upturn after the initial lockdown period ended in July. Prior to the lockdown speeds had declined slightly in all areas except inner SW London.


Compared with Q2 a year ago, EWT was significantly improved but was worse than Q1. The dual Covid19 impacts of reduced passenger numbers and less traffic disruption continued to have a boosting effect on reliability. 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 initial lockdown inner London had improved compared with last year whilst outer London had recorded a deterioration but the gradual return towards more normal levels in Q2 was 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 Q2.



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.