The Alphabet-owned self-driving car company will receive its order later this year, although the exact number of minivans destined to join Waymo's fleet has not been disclosed.
On Tuesday, Fiat Chrysler Automobiles (FCA) said the order builds upon 100 Pacifica Hybrid minivans already purchased by Waymo in 2016, and an additional 500 in 2017.
The minivans in question are not the sort you usually see on the road, however, as they have been specifically adapted for Waymo's autonomous vehicle dreams.
Waymo began testing driving the minivans last November on public roads -- without drivers. The vehicles are the first to attain a Level 4 in autonomy, which the Society of Automotive Engineers stipulates as a "high level."
While not fully autonomous, Level 4 vehicles can handle driving in a range of conditions and environments -- although not all -- and when conditions allow, drivers can hand over control to their transport.
In comparison, Level 5 only requires a driver to set the destination and allow the vehicle to make all transport decisions along the way.
Now that Level 4 has been achieved, Waymo hopes to open its autonomous ride-hailing service to the public this year in Phoenix, Arizona.
According to the company, "the additional Pacifica Hybrid minivans will be used to support Waymo as it expands its service to more cities across the United States."
Waymo has clocked over four millions of miles in testing on public roads and billions of miles in simulated tests.
Chrysler says that collaborative effort between the firm and Waymo's staff has enabled the teams to build adapted vehicles on a mass scale.
"In order to move quickly and efficiently in autonomy, it is essential to partner with like-minded technology leaders," said Sergio Marchionne, Chief Executive Officer of FCA. "Our partnership with Waymo continues to grow and strengthen; this represents the latest sign of our commitment to this technology."
In September, Intel and Waymo revealed a working partnership to develop vehicles capable of Level 4 and Level 5 autonomy. Together, Intel and Waymo have logged three million miles of real-world driving, and they hope to one day create cars capable of driving safely without the need for human interaction.