Final scores methodology

The component indicators

The final score for each borough is created using the methodology set out below. It is created from nine component indicators, the detailed results for which are displayed in Results: outcome indicators and Results: input indicators. Those pages also show the data sources and graphs/charts for each indicator (i.e. they display the data before it is later normalised for use in the index itself).

Background Information

1. Inner/Outer London Boroughs
The definition of the inner and outer London borough is that used for the London Plan. Of the total of 33 London boroughs (including the City of London), 14 are defined as Inner London and 19 as Outer London.

In 2021, the Healthy Streets Scorecard switched two boroughs’ designations to match TfL’s approach. So Greenwich is now counted as an outer London borough, and Haringey an inner London borough.

Inner London

Camden
City of London
Hackney
Hammersmith & Fulham
Haringey
Islington
Kensington & Chelsea
Lambeth
Lewisham
Newham
Southwark
Tower Hamlets
Wandsworth
Westminster

Outer London

Barking & Dagenham
Barnet
Bexley
Brent
Bromley
Croydon
Ealing
Enfield
Greenwich
Harrow
Havering
Hillingdon
Hounslow
Kingston upon Thames
Merton
Redbridge
Richmond upon Thames
Sutton
Waltham Forest

2. Road length

In relation to the length of protected cycle tracks, each of these elements of component data have been adjusted to take into account the total road length in the borough (as these lengths of road differ so significantly between the 33 London boroughs). The data is, therefore, adjusted to create a ratio that reflects the road length of the borough.

Below is a table of the road length of each London borough used for Scorecard data. The source of the Healthy Streets Scorecard (HSS) data comes from the Department for Transport and is Total road length (kilometers) by road type and local authority in Great Britain; for 2019 Scorecard data worksheet: RDL0102a_(2017), for 2020 Scorecard data worksheet: RDL0102a_(2019) and for 2021 Scorecard data worksheet: RDL0202a_(2020).

Road length in London in 2020 (HSS 2021) totalled 14,806 kilometers.

BoroughRoad length (km), HSS 2021
Barking & Dagenham340.4
Barnet764.3
Bexley550.5
Brent489.3
Bromley904.2
Camden278.7
City of London 55.4
Croydon776.8
Ealing587.7
Enfield636.6
Greenwich505.4
BoroughRoad length (km), HSS 2021
Hackney270.9
Hammersmith & Fulham219.8
Haringey356.1
Harrow475.8
Havering659.7
Hillingdon763.3
Hounslow501.6
Islington237.9
Kensington & Chelsea206.6
Kingston upon Thames344.4
Lambeth377.0
BoroughRoad length (km), HSS 2021
Lewisham446.7
Merton378.0
Newham429.5
Redbridge534.0
Richmond upon Thames412.7
Southwark390.9
Sutton433.0
Tower Hamlets285.6
Waltham Forest424.1
Wandsworth431.9
Westminster337.4

3. School Streets methodology

Primary and secondary schools have been identified by their Unique Reference Numbers (URNs). Schools with separate infant and junior schools and with different URNs have been included separately.

The total amount of schools in a borough (used to work out the proportion of schools with School Streets/total schools) have been identified from the Department for Education’s register for educational establishments in England and Wales, Edubase, and restricted to:

  • All schools in London
  • Excluding children’s centres; universities or educational establishments where the maximum age is over 20; ‘other’ educational establishments (e.g. secure units or learning support centres); or virtual organisations (e.g. a sixth form consortium)
  • Excluding establishments where the number of pupils is <20

The data on School Streets has been compiled by Healthy Streets Scorecard and Mums for Lungs.

 

Calculating the index (final scores)

The raw data from each of the component indicators was gathered by borough (see below). In several cases (e.g. protected cycle track), the original data was modified to take account of the length of roads of each borough.

In this description of the methodology, the boroughs are shown in alphabetical order.

For each of the indicators, the maximum and minimum data point was identified and a figure in the range of 0 to 1 was apportioned to the performance of each borough in terms of where it sits in the range between 0 and 1 (where 1 represents the best performance by a borough for that indicator in terms of Healthy Street performance, and 0 the least good performance by a borough for that indicator).

This method of using a range from 0 to 1 has been selected so that no borough can perform extremely well or poorly in relation to any single indicator. This was a danger where, for example, variation from the average was chosen as the way of developing the index.

In the case of seven of the nine indicators (Modeshare, Active Travel, LTNs, 20mph, CPZ Coverage, Length of Protected Cycle Track and Schools Provision) and half of the Car Ownership indicator (Households with no car), the higher the raw data score the better the performance and thus the higher the resulting index score. In the case of one indicator, Road Casualties and half of the Car Ownership indicator (Cars per household), a lower score in the raw data was deemed a better score in relation to the Healthy Streets Scorecard. For these latter indicators, therefore, the lowest raw data scores gained the highest Index scores.

For the Active Travel Indicator, the indicator score has been divided equally between the Walking score and the Cycling score so that each has a weighting of 0.5. Similarly, for the Road Casualties Indicator (divided equally between Pedestrian KSIs and Cyclist KSIs)*, Car Ownership Indicator (divided equally between Cars per household and Households with no car) and the Schools Provision Indicator (divided equally between STARS and School Streets).

* The Road Collision Casualty indicator uses a different approach from 2021 (prior to 2021, calculations combined pedestrian and cyclist KSIs, from 2021 these have been separated, and 2019 & 2020 scores retrospectively recalculated).

The chart (below, in two images) shows the resulting Index scores for each borough for each indicator where 1 is score of the borough performing best for that indicator in relation to Healthy Streets and 0 is the score of the borough performing the least well on this occasion:

The sum of these scores was totalled. The resulting score for these 9 indicators was multiplied by 10/9 to give a score out of 10. This is the 2021 Scorecard overall score given to each borough (as seen in the Your borough map).

To compare index scores between 2020 and 2021 the newest indicator (School Provision) was included (this was only added for 2020 so no comparison is possible for 2019). The 2019 index score is the resulting score of the 8 indicators (without School Provision) multiplied by 10/8 to give a score out of 10.

The resulting score for 2019, 2020 and 2021 when factored to be out of 10 appear left.*

Should, in the future, more indicators be added, the final index will always be a score out of 10.

* The overall scores for 2019 and 2020 have been retrospectively recalculated to account for Road Collision Casualty indicator changes. Some minor changes in the score and ranking has occurred. The comparison charts for overall scores for 2019, 2020 and 2021 Scorecard data use this adjusted data.

Download the London Boroughs Healthy Streets Scorecard (2021) indicator charts

Download the London Boroughs Healthy Streets Scorecard (2021) indicators data