Send to

Choose Destination

Health impacts of the M74 urban motorway extension: a mixed-method natural experimental study.


Southampton (UK): NIHR Journals Library; 2017 Apr.
Public Health Research.

Author information

Medical Research Council (MRC) Epidemiology Unit and Centre for Diet and Activity Research (CEDAR), School of Clinical Medicine, University of Cambridge, Cambridge, UK
Medical Research Council/Chief Scientist Office (MRC/CSO) Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK
Centre for Research on Environment, Society and Health, Institute of Health and Well-being, University of Glasgow, Glasgow, UK
NHS Greater Glasgow & Clyde, Glasgow, UK
Glasgow Centre for Population Health, Glasgow, UK
Norwich Medical School and Centre for Diet and Activity Research (CEDAR), University of East Anglia, Norwich, UK
Department of Social Policy and Intervention, University of Oxford, Oxford, UK
School of Exercise and Nutrition, Deakin University, Geelong, VIC, Australia
Physical Activity for Health Research Centre, University of Edinburgh, Edinburgh, UK



Making travel easier can improve people’s access to opportunities, but motor transport also incurs substantial undesirable health and social impacts.


To assess how a new urban motorway affected travel and activity patterns, road accidents and well-being in local communities, and how these impacts were experienced and brought about.


The Traffic and Health in Glasgow study, a mixed-method controlled before-and-after study.


Glasgow, UK.


Repeat cross-sectional survey samples of 1345 and 1343 adults, recruited in 2005 and 2013, respectively. Of these, 365 formed a longitudinal cohort, 196 took part in a quantitative substudy using accelerometers and global positioning system receivers and 30, living within 400 m of the new motorway, took part in a qualitative substudy along with 12 other informants. Complementary analyses used police STATS19 road traffic accident data (1997–2014) and Scottish Household Survey travel diaries (2009–13).


A new 5-mile, six-lane section of the M74 motorway, opened in 2011 and running through predominantly deprived neighbourhoods in south-east Glasgow, with associated changes to the urban landscape.


Differences in self-reported travel behaviour (1-day travel record), physical activity (short International Physical Activity Questionnaire) and well-being [Short Form 8 Health Survey (SF-8) and a short version of the Warwick–Edinburgh Mental Well-being Scale], and in the incidence of road traffic accidents.


A combination of multivariable cohort, cross-sectional, repeat cross-sectional and interrupted time series regression analyses comparing residents of the ‘M74 corridor’ intervention area and two matched control areas, complemented by novel qualitative spatial methods. Graded measures of the proximity of the motorway to each participant’s home served as a further basis for controlled comparisons.


Both benefits and harms were identified. Cohort participants living closer to the new motorway experienced significantly reduced mental well-being (mental component summary of the SF-8 scale) over time compared with those living further away [linear regression coefficient –3.6, 95% confidence interval (CI) –6.6 to –0.7]. In the area surrounding an existing motorway, this association was concentrated among those with chronic conditions. In repeat cross-sectional analyses, participants living closer to a new motorway junction were more likely to report using a car at follow-up than those living further away (odds ratio 3.4, 95% CI 1.1 to 10.7). We found weaker quantitative evidence of a decline in physical activity participation and no quantitative evidence of an overall change in either active travel or accidents associated with motorway exposure. Qualitative evidence suggested that, although the new motorway improved connectivity for those with dispersed social networks and access to motor vehicles, the impacts were more complex for others, some of whom found the motorway to be a cause of severance. Changes in community composition and cohesion, and perceptions of personal safety, were widely perceived as more important to local people.


A key limitation of natural experimental studies is that the risk of residual confounding cannot be eliminated.


Overall, these findings highlight the potential for urban infrastructural projects of this kind to add further burdens to already disadvantaged communities, exacerbating inequalities and contributing to poorer health outcomes. The health and social impacts of such initiatives should be more fully taken into account in planning and research.


The National Institute for Health Research Public Health Research programme.

Copyright © Queen’s Printer and Controller of HMSO 2017. This work was produced by Ogilvie et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.

Support Center