Before October, 1924 car manufacturers tested their cars on public roads.

That all changed when General Motors bought some land in rural Milford, Michigan, then about a day’s drive from Detroit, and built the world’s first automotive proving grounds.

The original site consisted of a just 6.4 km of gravel roads, while the entire facility was only 4.6 sq km in size — and had a single employee to do all the maintenance.

Later, as it was used more often, accommodation units were built on-site so testers could spend the week there.

The idea of a test track caught on quickly and in 1925 Ford opened its own proving ground in Dearborn.

Now almost every mainstream car manufacturer has one or more of them — for hot and cold weather testing.

These days GM’s Milford complex employs over 3000 professionals.

It covers 25 sq km and has 212km of road, from straightaways to loops, dirt, mud, tar and cobblestones.

There’s also an area known as The Black Lake, 30ha of flat pavement, where cars can be driven at top speed and tested under varying surface conditions.

In a video released celebrating Milford’s contribution to GM’s history, clips of crash tests from the late 1920s and early 1930s show drivers jumping from vehicles just before they hit the crash barriers.

GM has used the testing grounds to develop and test countless new models.

Prototypes of the 1948 FX Holden were initially tested at Milford.

The crash test dummy was also perfected at Milford.

In the early 1980s, a GM safety team built a human dummy for crash tests which quickly became the universal standard and remains so today all over the world.

It was at Milford that one of GM’s most iconic cars was created.

On a Saturday morning in March, 1963, John Z. De Lorean, the boss of Pontiac, his adverting guru, Jim Wangers, and engineers Russell Gee and Bill Collins, were testing the new lightweight Pontiac Tempest.

It was Collins who observed “You know, we could put the big 6.5-litre V8 out of the Bonneville into this thing, and I bet it would be really quick”.

Next week they were back at the proving ground with the bigger motor fitted in the Tempest.

The car was awesomely quick, and the team knew they had a winner.

Later they gave it a name: GTO.

And the rest, as they say, is history.

David Burrell is the editor of retroautos.com.au

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Burrell

David Burrell is founder and editor of Retroautos.com.au, a free online classic cars magazine. Dave has a passion for cars and car design. He's also into speedway, which he's been writing about since 1981. His first car was a rusted-out 1961 Vauxhall Velox. His daily driver is a Pontiac Firebird. Prior to starting Retroautos, David was an executive in a Fortune 500 company, working and living in Australia, NZ, Asia, Latin America and the UK.