Yes, it could work. Or the driver's secretly also a spy from some kind organization.
While taking passengers also searching for targets.
I wouldn't go that far to make them spies, espionage or anything. Or at least they will occaisonally work for some law enforcement. Like some of your passengers to pick up can either be a cop, a terrorist or thrill seekers that will ask for an objective other than a destination. Such as "Stop that car!" or "Crash into that!" or "Drive off this ramp!" sort of thing.
As for a proper story, I dunno. I imagine most taxicab businesses hate
Uber so maybe a parody of Uber (I'm thinking "Oobre") made into an antagonist.