1. D. Rachel Lombardi is in the Department of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK,
2. Libby Porter is in the Department of Urban Studies, University of Glasgow, 25 Bute Gardens, Glasgow, G12 8RS, UK,
3. Austin Barber is in the Centre for Urban and Regional Studies, University of Birmingham, Birmingham, UK,
4. Chris D.F. Rogers is in the Department of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK,