It's a perfectly fine objective if you trust your drivers to meet a minimum standard of a good job. It won't work in an adversarial system like Uber where drivers are just numbers but if the drivers are also invested in the success of the platform it's fine.
Given that drivers are driving the shorted distance/time route at the speed limit, treating customers with respect, arriving on time to scheduled pickups, etc. The next thing to focus on is scheduling/filling orders such that drive time is maximised.
Given that drivers are driving the shorted distance/time route at the speed limit, treating customers with respect, arriving on time to scheduled pickups, etc. The next thing to focus on is scheduling/filling orders such that drive time is maximised.