Civic planning is a tough gig, because your ability to experiment with new ideas is limited – you can’t just knock down a housing estate to see how it changes the traffic flow, for instance. Which makes it an obvious market for computer modelling, with a team at Arizona State developing sophisticated simulations of human crowd behaviour to help planners and architects make cities safer and more efficient. Which is all well and good, I suppose – but will it lead to the increased homogenisation of urban spaces? And how will they factor in the ways that people change the use of objects and spaces over long periods of time? And how much more complicated do these simulations have to become before turning them off becomes a question of ethics?