Table 2.

Study metrics and optimisations

Metrics definition
Timeall	Average travel time to the nearest hospital in the population
Timepoor	Average travel time to the nearest hospital for the poorest 10% of pixels
Timerich	Average travel time to the nearest hospital for the richest 10% of pixels
Optimi s ations
Efficiency	min(timeall)
	Minimise overall travel time to the nearest hospital in the population
Equity gap	min(abs(timepoor – timerich))
	Minimise absolute difference between travel time to the nearest hospital for the poorest and for the richest decile