Concepts · 2009
The car that brakes with an airbag.
For thirty-five years, Mercedes built no experimental safety vehicle. Then it built one that inflates its own body — and throws an airbag at the road.
Stuttgart, June 15, 2009. Not a motor show — the Enhanced Safety of Vehicles conference, where crash researchers present papers to other crash researchers. Mercedes brings a white S-Class in black and orange warpaint, and a sentence nobody expected: this is the first ESF since 1974.
ESF — Experimental-Sicherheits-Fahrzeug. In the early 1970s these rolling laboratories, built for the international Experimental Safety Vehicle program, pioneered ideas the whole industry later adopted. Then the program went quiet for a generation. The ESF 2009 was Mercedes picking the thread back up, in public.
Chapter I
The inflatable car.
The ESF 2009 — built on an S 400 HYBRID — carried more than a dozen working experiments, and the wildest lived under the floor. The Braking Bag is an airbag with a friction coating that fires downward in the last moments before an unavoidable impact, pressing against the road to slow the car harder, lift its nose, and cancel brake dive so the crash structures meet the collision square-on.
Just as strange: PRE-SAFE Structure — body sections made of folded metal that a gas generator inflates to 10–20 bar within fractions of a second, turning a light, space-saving profile into a rigid crash member only when one is needed.
The rest of the car was a catalog of nearer futures: an inflatable seat-belt strap to spread chest loads, an airbag between the front seats, seats that nudge occupants inboard before a side impact, headlamps that stay on main beam while masking oncoming traffic, a spotlight that literally points out pedestrians, and Car-to-X radio so vehicles could warn each other about hazards neither driver had seen yet.
None of it was decoration. Every system worked — and most of it was in showrooms within five years.
From lab to showroom
Where the ESF 2009’s experiments ended up
- Beltbag inflatable seat belt
- 2013 · S-Class (W222)
- Spotlight function
- 2011 · CL-Class (C216), as Night View Assist Plus
- Car-to-X communication
- 2013 · S-Class (W222)
- PRE-SAFE Impulse
- 2013 · S-Class (W222), side version E-Class 2016
- Partial main beam LED
- 2013 · S-Class (W222), as Adaptive Highbeam Assist Plus
- Braking Bag
- — · Still experimental
Epilogue
A tradition, restarted.
The ESF 2009 did exactly what its 1970s ancestors had done: made safety research visible, then quietly fed it into production cars. The Beltbag, the center airbag, PRE-SAFE Impulse, Car-to-X — all of it traces back to this one white test mule. And the tradition it revived didn’t lapse again: ten years later, Mercedes built the next one, the ESF 2019.