The four-story factory stretches for half a kilometer. Lingotto is arguably the most famous building in Turin, a city so closely tied to Fiat that it is part of the company’s name: Fabbrica Italiana di Automobili Torino. That’s because it was used as a filming location for part of the climactic chase scene in the original The Italian Job starring Michael Caine. The first, Fiat’s former Lingotto factory in the middle of Turin, is fairly well known even to some folks who aren’t car enthusiasts.

If next door is convenient, how about putting the test track in-or I should say on-the factory itself? Might not have been your first thought, but that’s exactly what at least three car companies did in Italy, Argentina, and Belgium: They put test tracks on the roofs of their factories. For example, in addition to Ford’s tracks in Dearborn and Romeo, its transmission plant in Livonia, Michigan, also has its own little-known, oval test track right next door. Not every car company had the option of using thousands of acres of land for testing, and while there are all sorts of tests that can be accomplished at a large test track, including high-speed and endurance testing, it’s also nice to be able to do some immediate real-world testing. A bit farther west, Chrysler dedicated a 3850-acre facility in Chelsea in 1954, and Ford built its own exurban test track on its 3880-acre proving grounds in Romeo soon after. In 1924 General Motors started developing its 4000-acre proving grounds in Milford, about a half hour northwest of Detroit. As Detroit and its suburbs developed, the major automakers followed Packard’s lead, taking advantage of the open spaces in the regions beyond the city.

Packard even built a small private airport on the track’s infield and constructed an engineering lab adjacent to the track. Packard, on the other hand, decided to build a modern, high-speed, 2.5-mile squared oval test track-as fast as the speedway in Indianapolis, in fact-at what it named the Packard Proving Grounds in Shelby Township, about 20 miles north of the Packard plant on Detroit’s east side. Ford converted Ford Airport, on the grounds of its own Dearborn complex, to what would become the Dearborn Proving Grounds in the late 1930s.

Detroit city airport race track