Ford is road testing its autonomous vehicles in partnership with the city of Miami, as the legacy automaker hopes to capitalize on the emerging technology in ride-share and business delivery.

The automaker has been testing a Ford Fusion equipped with autonomous vehicle tech, or AV, in Miami since February. It chose the city because of its congestion and the unpredictability of the traffic there. Tests are also being done in three other cities: Pittsburgh, Detroit and Washington, D.C.

Ford has said it plans to begin selling self-driving cars by 2021, but it is also testing out ways it can use these vehicles to carry people and things. Sherif Marakby, CEO of Ford Autonomous Vehicles, told CNBC the company is focused on profitability and scalability.

"We're laser focused on profitability," said Marakby, who said autonomous vehicles provide transportation at a lower cost than current vehicles. "While the vehicle is expensive, initially we're deploying it in service so the cost per mile for transportation for a person or a business is going to be lower and will be profitable for us," he said.

Ford has said it plans to invest a total of $4 billion into AV technology through 2023.

On Wednesday, the company announced a partnership with Walmart and Postmates to collaborate on a delivery service that will one day use autonomous vehicles.

During a test ride with CNBC, Ford used a car that was autonomous, however, it did travel along a predetermined and pre-programmed route. Ford also manned the vehicle with a safety driver, whose hands hovered over the wheel, which the company said was a "precaution."