These people willingly took a job that requires them to transport ANYONE unless they appear dangerous or threatening. If they don't want their "faith violated" then they are free to seek employment elsewhere and stop pretending that their "faith" is being violated.
BINGO.
Someone who wants to “adhere to their faith” should choose a job that does not involve transporting alcohol-toting, dog-owning infidels. Don’t get into customer service and then refuse to serve the customer.
Or perhaps limit their taxi service to serving mosques and halal markets.