1. Chui, M., Manyika, J. & Miremadi, M. McKinsey Quarterly (2016); available at http://go.nature.com/2xt0iio
2. Cowen, T. Marginal Revolution (2013); available at http://go.nature.com/2kzkkgs
3. World Health Organization Global Status Report on Road Safety 2015 (WHO, 2016).
4. Fagnant, D. J. & Kockelman, K. Transp. Res. Part A Policy Pract. 77, 167–181 (2015).
5. Azimi, S., Bhatia, G., Rajkumar, R. & Mudalige, P. SAE Int. J. Passenger Cars — Mech. Syst. 4, 406–416 (2011).