1 School of Electronic, Electrical and Systems Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. Electronic address: c.baber@bham.ac.uk.
2 Future Mobility Group, School of Engineering, Newcastle University, Stephenson Building, Newcastle upon Tyne, NE1 7RU, UK.
3 Human Factors and Complex Systems Group, Loughborough Design School, Loughborough University, Loughborough, LE11 3TU, UK.