Do 20mph speed limits reduce casualties and increase cycling, walking, and liveability in the general population?

Is 20 plenty for health? Evaluation of the 20mph speed limit networks in Edinburgh and Belfast on a range of public health outcomes

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN10200526

Enrollment

Registered

2017-03-29

Start date

2018-05-01

Completion date

Unknown

Last updated

2022-11-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Public health Not Applicable Public health

Interventions

20mph speed limits are introducted across the cities of Edinburgh and Belfast relying primarily on legislation, signage, education and road markings. The study uses a combination of r

Sustrans

and Living Streets. Data will be collected at baseline and at various time points post implementation (depending on the outcome being measured). Follow up of all outcomes will be at least 12 months, w

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Living in Edinburgh, Scotland and Belfast, Northern Ireland or travelling regularly into the cities for the purpose of work, study or other reason. 2. Aged 18 years and over 3. Primarily travel using a motorised vehicle (e.g. car, van, motorcycle, moped)

Exclusion criteria

Exclusion criteria: Not living or working in Edinburgh or Belfast.

Design outcomes

Primary

Measure	Time frame
Casualty data is taken from STATS19 accident records (collected nationally by the police) at multiple time points pre and post implementation (up to 18 months) of the 20mph zones.	—

Secondary

Measure	Time frame
1. Walking is assessed through automatic fixed pedestrian counters (collected by Sustrans) and using Route User Surveys (collected by Sustrans) at multiple time points before and after (up to 18 months) implementation of the 20mph zones 2. Cycling is assessed through automatic fixed cycling counters (collected by Sustrans) and using Route User Surveys (collected by Sustrans) at multiple time points before and after (up to 18 months) implementation of the 20mph zones 3. Public transport use is assessed through routine bus data (collected by the bus companies) at multiple time points pre and post implementation (up to 18 months) of the 20mph zones 4. Attitudes towards 20mph zones are collected through the Edinburgh Household Survey at baseline and 12 months post implementation of the 20mph zones 5. Traffic and speed volume is collected through a survey at baseline and 18-months post implementation 6. Perceptions of public support, behaviour and compliance are collected through a survey at baseline and 18-months post implementation 7. Liveability is assessed using street audits (by Living Streets) at baseline and 12 baseline and 18-months post implementation	—

Measure

Time frame

1. Walking is assessed through automatic fixed pedestrian counters (collected by Sustrans) and using Route User Surveys (collected by Sustrans) at multiple time points before and after (up to 18 months) implementation of the 20mph zones 2. Cycling is assessed through automatic fixed cycling counters (collected by Sustrans) and using Route User Surveys (collected by Sustrans) at multiple time points before and after (up to 18 months) implementation of the 20mph zones 3. Public transport use is assessed through routine bus data (collected by the bus companies) at multiple time points pre and post implementation (up to 18 months) of the 20mph zones 4. Attitudes towards 20mph zones are collected through the Edinburgh Household Survey at baseline and 12 months post implementation of the 20mph zones 5. Traffic and speed volume is collected through a survey at baseline and 18-months post implementation 6. Perceptions of public support, behaviour and compliance are collected through a survey at baseline and 18-months post implementation 7. Liveability is assessed using street audits (by Living Streets) at baseline and 12 baseline and 18-months post implementation

—

Countries

Northern Ireland, Scotland, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 11, 2026