Self-driving passenger vehicles have officially hit the road.

Uber launched its trial fleet in Pittsburgh today, making the ride-hailing company the first to make self-driving cars available to the American public.

Company officials say they are prepared for the endeavor, citing the data gathered from the ride-hailing service's drivers.

"If you think about it, every month Uber drives over a million miles, and that gives us insight into how the city works," said Anthony Levandowski, Uber's vice president of self-driving technology. "Where are people driving? Where are they getting into accidents?"

One of the company's main driving forces (pun intended) is to reduce accidents. Raffi Krikorian, director of Uber's Advanced Technology Center in Pittsburgh, said 1.3 million people are killed annually in car crashes, with the vast majority of those -- 94 percent -- involving human error.

"We strongly feel that self-driving technology can make a dent in these statistics," he said.

Most modern drivers are already familiar with some level of autonomy, such as anti-lock brake systems and adaptive cruise control, which have been added to vehicles over the last several decades in the name of safety.

Uber's semi-autonomous cars are a few steps further, only needing a human driver for certain maneuvers. Those include parking, driving in inclement weather and driving through areas with flaggers. The technology currently reads all pedestrians alike and cannot follow the specific movements of a crossing guard or construction worker. In these instances, the human operator will take control.

During the Pittsburgh trial, each self-driving Uber will have a trained vehicle operator behind the wheel and a testing engineer to analyze data.

An Uber operator parks a self-driving car at the company's Advanced Technologies Center in Pittsburgh. Human drivers are still needed for parking and other maneuvers.

So why did the company pick Pittsburgh? That comes down to several factors: government, technology, infrastructure and environment.

Pennsylvania law is essentially silent regarding self-driving vehicles, which has been interpreted by local officials as a green light. In particular, Mayor Bill Peduto has been a major supporter of Uber's efforts.

Another bonus to setting up shop in Steel City is that the local technological industry provides ample room for growth and new employees.

Lastly, the combination of city infrastructure and weather means more opportunity for gathering data.

The sensors are weatherproof, and the vehicles will drive in inclement weather as long as the operator feels it is safe to continue. Weather-specific testing will also continue on closed tracks.

"Pittsburgh is an old city," Krikorian said. "It has an organic road network, it has real traffic problems, it experiences extreme weather. So we really feel that Pittsburgh is the double black diamond of driving."

Mastering self-driving technology under such conditions, he said, would make it significantly easier to expand the service to other cities.

For now, the company will allow its best Pittsburgh customers to opt in to the trial. When one of those riders is looking to hail a ride within the testing zone -- downtown, the Strip District, and parts of the North Shore and neighborhoods south of downtown -- they may end up inside a self-driving Ford Fusion or Volvo XC90.

This detail image shows the top-mounted lidar system, which rotates for a 360-degree scan, above the traffic light camera and another camera array on one of Uber's self-driving Ford Fusions.

The technology between the vehicles is similar, though the Volvo is newer and more streamlined as a result of the automaker's relationship with Uber.

Pittsburghers are more likely to see the Ford Focus on the road, at least to start. It has a top-mounted lidar scan -- like radar, but with lasers instead of electromagnetic waves -- for a 360-degree view of the car's surroundings.

"It actually has 64 lasers in it, and they fire at really high frequency," said Eric Meyhofer, lead of Uber's hardware team. "It's around 1.4 million range points per second, and it rotates, so it sweeps the world and makes a three-dimensional map."

The lasers, however, cannot read color. The camera located directly below the spinning lasers is for interpreting traffic lights. Below that is yet another array of cameras, and radar sensors are embedded in the grill and surrounding the vehicle.

In addition to live feedback while driving, technicians check the equipment daily to ensure it is functioning properly.

Now, Uber's self-driving fleet is not the first of its kind. That honor goes to nuTonomy, which debuted its semi-autonomous taxi service in Singapore a few weeks ago.

The developer, founded by two MIT graduates, has been testing its autonomous vehicles in Singapore's one-north district since April. NuTonomy's public trial consists of six cars allowed to operate in the 2 1/2-square mile district, with designated pick-up and drop-off locations. The company hopes to launch a full fleet by 2018.

Uber is starting with just a handful of self-driving cars in Pittsburgh, with plans to rapidly expand the fleet as testing proceeds. By the end of the year, Uber hopes to have 100 Volvos on the streets.