The act of hailing taxis is being transformed by new mobile technologies.

Start-ups like Uber, Lyft and others are introducing app-hailed car services that are upending the traditional model of waving down a taxi from the street.

And it seems that the taxi industry could get even more competition now that regulators are signaling that new services can operate as long as they abide by the rules of the Taxi and Limousine Commission. Those rules include drug tests for drivers, criminal background checks, insurance and more.

amNewYork took a look at some of the new apps and how they work. Some of the apps only work with yellow (or green) cabs, while others are proprietary to livery or black cars. Some services even offer luxury cars and SUVs.