1 - how is actual Excess Waiting Time (EWT) raw data obtained for bus routes, and how is it turned into the relevant figure? 2 - How often is the EWT for each [unchanged] bus route revisited? 3 - Is EWT calculated for every bus route? 4 - Does bus EWT vary by hour of day, day of week and/or time of year? 5 - Is bus EWT only determined for one point or on direction along each route or is bus EWT done for multiple locations per route and different times of day /days of week etc? 6 - How long after an existing bus route is significantly altered, or a new route's introduction is an EWT calculated? 7 - what would be determined as a 'significant change' to cause a new EWT to be measured? 8 - do you publish previous and new EWTs to enable comparisons?

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TfL Ref: 0791-1920

Thank you for your request received by us on 18 June 2019 asking for information about Excess Waiting Times (EWT) on the London Buses network.

Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy. I can confirm that we hold the information you require.

Excess Waiting Time represents the amount of time a passenger has had to wait in excess of the time they should expect based on the given schedule. The EWT is the difference between the Actual Waiting Time (AWT) and the Scheduled Waiting Time (SWT).

Whilst your request references Excess Waiting Time, the majority of the questions seem more appropriate to the EWT Minimum Performance Standards rather than EWT itself. This is because the EWT Minimum Performance Standard (MPS) is a performance value a route is expected to achieve. Bus Operators are incentivised to achieve an EWT figure that is less than or equal to the Minimum Performance Standard.

You asked for the following information:

1 - How is actual Excess Waiting Time (EWT) raw data obtained for bus routes, and how is it turned into the relevant figure?
I can advise that the EWT MPS is set at the beginning of each contract. The MPS value takes into account various factors such as route geography (central London or suburbs), route length and whether it runs through major centres, major corridors, traffic hotspots or narrow roads. Stand constraints are also included in recognition of the fact that there may be restrictions imposed upon the length of time to be spent. Any variables wholly within the control of Bus Operator are ignored.

The EWT is the difference between the Actual Waiting Time (AWT) and the Scheduled Waiting Time (SWT). The SWT is calculated from scheduled headways between buses, while the AWT is calculated from actual headways between buses.

2 - How often is the EWT for each [unchanged] bus route revisited?
Although the EWT MPS often remains unchanged throughout the term of the contract it will be reviewed in respect of any mid-contract changes to structure or frequency and the MPS may be revised accordingly.

The EWT cannot be revised as this measure shows what route actually achieves at any time period.

3 - Is EWT calculated for every bus route?
Both EWT and EWT MPS are calculated for High Frequency routes only. High frequency routes generally operate five or more buses an hour during weekdays.

4 - Does bus EWT vary by hour of day, day of week and/or time of year?
Once set, the EWT MPS becomes applicable to all seasons, day types and hours of day.

Actual EWT is likely to vary by hour, day and time of year.

5 - Is bus EWT only determined for one point or on direction along each route or is bus EWT done for multiple locations per route and different times of day /days of week etc?
Once set, the EWT MPS becomes applicable to all directions and points.

The data for EWT calculations is collected at multiple locations at all times and days of the week.

6 - How long after an existing bus route is significantly altered, or a new route's introduction is an EWT calculated?
The EWT MPS is defined prior to any structural or frequency change for a route. This is usually takes place several months prior to introduction of the change.

Route level EWT results are published in the Quarterly Network Performance Summary reports via the following link to our website: . https://tfl.gov.uk/corporate/publications-and-reports/buses-performance-data

7 - what would be determined as a 'significant change' to cause a new EWT to be measured?
A route extension or shortening of route, a re-routeing or frequency change would generate a review of the MPS.

8 - do you publish previous and new EWTs to enable comparisons?
This information can be found in the various performance reports we publish here at route level: https://tfl.gov.uk/corporate/publications-and-reports/buses-performance-data

The Quality of Service Indicator reports also provide further information here: https://tfl.gov.uk/forms/14144.aspx

In accordance with section 21 of the FOI Act, we are not obliged to supply you with a copy of the requested information as it is already accessible to you elsewhere.

If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate to contact me.

Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.

Yours sincerely

Jasmine Howard
FOI Case Officer
Information Governance
Transport For London

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