There's a startup called Flywheel that has been selling shovels to taxi cab companies -- in the form of electronic dispatch, payments, navigation and GPS-based metering.
And it works fine. I've been using Flywheel since 2013. Their software started out rough, but now it's solid. It may be a bit more expensive, but the average driver I get has been driving in SF more than a decade, so they're knowledgeable and competent. Plus I know they're insured and properly regulated.
https://techcrunch.com/2016/09/22/flywheel-expands-uber-like...