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.

Inner London

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

Outer London

Barking & Dagenham
Barnet
Bexley
Brent
Bromley
Croydon
Ealing
Enfield
Haringey
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 and the number of roads and streets in each borough which have been filtered, 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 (miles) by road type and local authority in Great Britain; for 2019 scorecard data worksheet: RDL0102a_(2017)
for 2020 scorecard data worksheet: RDL0102a_(2019)

Road length in London in 2017 (HSS 2019) totalled 9222 miles and in 2019 (HSS 2020) totalled 9205 miles.

BoroughRoad length (mi) HSS 2019Road length (mi), HSS 2020
Barking & Dagenham211.5211.6
Barnet474.0475.9
Bexley348.0342.2
Brent302.8304.2
Bromley563.1560.9
Camden175.6173.6
City of London34.334.5
Croydon483.5482.6
Ealing365.2366.2
Enfield398.0395.7
Greenwich312.3313.5

BoroughRoad length (mi), HSS 2019
Road length (mi), HSS 2020
Hackney172.2168.6
Hammersmith & Fulham137.2136.7
Haringey221.6221.6
Harrow294.6295.9
Havering410.5409.4
Hillingdon470.8473.3
Hounslow310.3312.7
Islington147.9147.9
Kensington & Chelsea127.3128.5
Kingston upon Thames214.2213.9
Lambeth238.0234.3

BoroughRoad length (mi), HSS 2019
Road length (mi), HSS 2020
Lewisham283.9277.9
Merton233.9235.2
Newham265.2267.2
Redbridge331.2331.8
Richmond upon Thames257.9257.1
Southwark244.4243.1
Sutton268.6268.8
Tower Hamlets177.2178.5
Waltham Forest264.4263.7
Wandsworth271.8268.7
Westminster211.1209.8

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. modal filtering and 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, Filtering, 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 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 chart (below) 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 2020 Scorecard overall score given to each borough (as seen in the Your borough map).

To compare index scores between 2019 and 2020 the newest indicator (School Provision) was removed (as this was only added for 2020 so no comparison is possible for 2019) and the resulting score of the 8 indicators was multiplied by 10/8 to give a score out of 10. The resulting score for 2019 and 2020 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.

Download the London Boroughs Healthy Streets Scorecard (2020) indicator charts

Download the London Boroughs Healthy Streets Scorecard (2020) indicators data