Low Traffic Neighbourhoods in London: baseline for a controlled before-and-after study

RESEARCH QUESTIONS: Do new Low Traffic Neighbourhoods (LTNs) lead to more, and more diverse, walking and cycling (active travel), compared to control areas? Does traffic displacement of motor vehicles lead to unintended consequences on boundary roads?

BACKGROUND: LTNs are transport interventions that remove or substantially reduce through motor traffic in residential streets. They involve street furniture such as planters, bollards, and gates; or camera-enforced closures. From a low baseline, LTNs were implemented at scale in 2020, as part of the UK’s Covid-19 response.

This was particularly the case in London, where 4% of the population (300,000 people) live in an LTN built March to September 2020. However, monitoring of LTN impacts has been patchy, often lacking ‘before’ data and typically lacking control sites – a key limitation given dramatic ongoing changes in travel behaviour.

AIM: We will collect baseline data for 6 new London LTNs being introduced in Autumn 2021. This will allow future analysis of how active travel and motor vehicle volumes change inside the LTNs and on boundary roads. OBJECTIVES: 1. To recruit 6 London local authorities that are planning 2021 LTNs. 2. To define 6 intervention and 6 matched control sites.

3. To collect 4 months baseline data for intervention and control sites. 4. To apply for follow-on funding for a full evaluation.

BASELINE METHODS: We will identify 6 proposed LTNs across 6 London boroughs, purposively sampled to cover different contexts (Inner/Outer London, different baseline travel patterns). For each we will sample one intervention and one boundary road site, matching each to a control site elsewhere in the borough. We will install Vivacity cameras which use algorithms to count different road user modes, also recording data such as speed.

Anonymised data will be provided in real-time to us. We will also use the Google API to sample a set of car journey times around each area. Additionally, we will use in-person observations to capture some of our proposed diversity of usage metrics.

Active travel and motor vehicle volumes are our primary outcome as (a) these are a key mediator of most potential health impacts of LTNs but (b) no routine datasets adequately capture these at street level.

FULL EVALUATION: We will apply for follow-on funding for: (a) follow-up data collection for 20 months (i.e. 24 months total); (b) complementary qualitative research; (c) secondary analysis of routine datasets to explore other health-related impacts (e.g. road traffic injury, street crime); and (d) modelling health and health economic impacts.

TIMELINES FOR DELIVERY: A further £20m Emergency Active Travel funding was announced for London in November 2020, with schemes needing to be delivered by March 2022. We will start recruiting boroughs in February and identify suitable intervention and control sites by April. Baseline counts will be set up from May, targeting LTNs due for implementation September-December 2021.

ANTICIPATED IMPACT AND DISSEMINATION: LTNs are often controversial so it is vital policy makers are rapidly provided with high-quality evidence on impacts. We will use our strong policy and practice networks to ensure that emerging evidence informs policy as soon as possible. Our team includes academics experienced at achieving impact, the PI having won in 2016 the ESRC Prize for Outstanding Impact in Public Policy.