Inside a Real Crash Report: How AI Reconstructs the 10 Seconds of an Accident

A road accident lasts, on average, less than a second. The argument about that instant can last months: who was doing what speed, who braked and who didn't, which direction the hit came from. We've already covered why crash analysis matters in an insurance claim; today we go one step further and open the actual document.

This article is a guided tour inside a crash report generated by the Mobisat system: section by section, field by field, with an explanation of what each value measures and why it's there. Not a brochure — the anatomy of the document a car owner (or their dealership) is looking at within minutes of an impact.

Where the report comes from

Before opening the document, a word on how it's generated — because this is the part that surprises people most: nobody fills it in.

The Greenbox Guardian AI device, plugged into the vehicle's OBD-II port, continuously records driving parameters and accelerometer data. When the acceleration magnitude crosses the thresholds typical of a collision, the system recognises the crash, freezes the data from the seconds around the event, and the AI analysis turns it into a readable report. The document arrives as a shareable link — viewable on a phone, printable as a PDF — without any human having to reconstruct anything from memory.

That detail is the essence of the entire product: the report is a transcription of what the sensors recorded as it happened. Not an after-the-fact assessment, not a witness statement. A recording.

Section 1: vehicle and header — who, what, when

The report opens the way an official record would: by precisely identifying the object and the context. Registration plate, VIN (chassis number), vehicle model and year; the customer's details; date and time of the event. Where the report is generated through a dealership using the Mobisat Service Portal, the dealership's name appears in the header as the provider.

It looks like paperwork; it's actually the foundation of the report's evidential value. Telematics data is only worth something if it's unambiguously tied to that vehicle at that moment. The VIN and the timestamp do exactly that.

Section 2: the impact in three numbers

Directly below, the report condenses the collision into three values:

• Severity — the classification of the event, from minor knock to serious impact. It frames how everything else should be read: documenting a car-park bump is one thing; a high-speed rear-end collision is another.
• Impact force, in mG — the magnitude of the acceleration the vehicle experienced at the moment of impact, measured in thousandths of g. It's the physical answer to "how hard was the hit?" — a question that insurance claims usually settle by eyeballing the bodywork.
• Speed at the moment of impact — the single most disputed number in any accident claim. Here it isn't declared; it's read from the vehicle.

Three numbers in, and the report has already answered the two questions that produce most disputes: how hard, and how fast.

Section 3: where — position and heading

The next section places the event in space: address, GPS coordinates and direction of travel in degrees. Positioning comes from the device's multi-constellation GNSS receiver (GPS, GLONASS, Galileo, BeiDou), the same one that powers the anti-theft tracking.

There's also a wider context the report can draw on: the device normally records position every 200 metres, every minute, and at every turn of 30 degrees or more. Which means the accident isn't an isolated dot on a map — it's the final frame of a continuous track: where the vehicle was coming from, along which route, at what pace. When the other party claims you arrived from somewhere else, the route history is already on record.

Direction of travel is the least flashy field and one of the most useful: cross-referenced with the impact angle in the next section, it lets you reconstruct how the vehicles were oriented relative to each other — the element that, in conflicting accounts of a junction collision, makes the difference between being right and being able to prove it.

Section 4: the impact angle — where the hit came from

Here the report enters territory no accident statement form can cover. A diagram of the vehicle — front, rear, right side, left side — shows the angle of impact in degrees and the impact type, derived by decomposing the forces recorded by the accelerometer across three axes:

• X force (longitudinal) — along the direction of travel: rear-end collisions and emergency braking live here;
• Y force (lateral) — perpendicular to travel: side impacts, junction hits;
• Z force (vertical) — the axis that reveals kerbs and bumps, and generally distinguishes a road impact from a jolt.

All three in mG, all three recorded in the same instant. The vector signature of a collision is hard to fake and even harder to argue with: if the dominant force is lateral-left, the hit came from the left — whatever the other party's version says.

Section 5: the 10-second timeline — the heart of the report

And here it is, the section this article is named after. The report reconstructs the 5 seconds before and the 5 seconds after the impact, second by second: −5s, −4s, −3s, −2s, −1s, CRASH, +1s, +2s, +3s, +4s.

In the interactive version of the report, every instant is clickable. For each second, the system shows the parameters read from the vehicle at that moment:

• Engine speed (RPM)
• Throttle position (%) — i.e. how much accelerator the driver was applying
• Speed (km/h)
• Ignition state (ON/OFF)
• X, Y, Z accelerations (mG) and the overall impact magnitude

It's the difference between a photograph and a film. The photograph of the moment of impact tells you how hard it was; the ten-second sequence tells you the dynamics. An illustrative example: a throttle dropping to zero and speed already falling at −3 seconds describe a driver who saw the danger and reacted; RPM and throttle steady until −1 second describe the exact opposite. The "after" matters just as much: the seconds following the impact — did the vehicle stop immediately? did the ignition stay on? — complete the reconstruction.

Closing the section are the accelerometer trace — the graphed progression of forces around the event — and the full telematics table, listing every value for all ten seconds, row by row: time, RPM, throttle, speed, X, Y, Z, magnitude. It's the least spectacular and most valuable part of the document: raw numbers, open to inspection by anyone who needs to verify them.

Section 6: the AI analysis — from numbers to narrative

Everything so far is data. The next section is the reason the report is readable by someone who has never seen an accelerometer: the AI analysis of the incident.

The AI takes everything the previous sections express numerically — severity, forces on three axes, angle, timeline — and returns it as a natural-language reconstruction of the dynamics: what the vehicle was doing, what happened at impact, what happened in the seconds after. It's the same approach Guardian AI applies to diagnostics (an OBD error code becomes a plain-language explanation with an estimated repair cost): data exists to be understood, not just logged.

An honest caveat is worth stating: the AI analysis does not assign liability — that remains the job of insurers, assessors and, when it comes to it, courts. What it does is make the objective data readable and coherent, so that your version of events is no longer just a version.

Section 7: sharing — the report that travels

The final section is operational: "Share with your insurer". Two buttons — copy link, print PDF — and the document is ready to be attached to a claim, sent to a claims handler, or handed to an assessor.

It's a product detail that hides the most important choice of all: the report belongs to the vehicle's owner. An insurance black box transmits data to the insurer, which interprets it by its own criteria; here the flow is reversed. The data originates on your device, the report comes to you, and you decide whether, when and with whom to share it.

The questions the report always raises

Walking through the document's anatomy tends to prompt the same three questions. Let's answer them straight away.

"Does it need complicated installation?" No. The device plugs into the OBD-II port, the standard fitted to every petrol, diesel and hybrid vehicle since 1996. No wiring, no workshop visit: the system that generates everything described above installs in seconds.

"What if the impact is minor?" That's exactly why the severity field exists. The system classifies the event, and this works in your favour in both directions: it documents how serious a major impact was, but it also certifies how light a minor one was. Faced with an inflated claim — the classic whiplash from a car-park tap — a report showing minimal forces and speed is a defence that simply didn't exist before.

"Who sees this data?" The device's owner. Mobisat's position on this is unambiguous: your data is yours, with full ownership, self-service deletion, and no selling to third parties. The report lives on your account and travels only through the link you choose to share. For anyone coming from the world of insurance black boxes, it's a complete reversal of the paradigm.

Finally, there's the dealership case: through the Mobisat Service Portal, the dealer who installed the device can generate the report and pass it to their customer under the dealership's own name. For the customer, it's a service no competitor offers at handover; for the dealer, a concrete reason that customer comes back.

What all this means in practice

To recap, a Mobisat crash report contains: certain identification of the vehicle (VIN, plate, date and time), the collision condensed into three numbers (severity, force in mG, speed), position and heading, the impact angle reconstructed from forces on three axes, the second-by-second timeline of the ten seconds around the crash with full engine parameters, the complete accelerometer trace, an AI analysis in natural language, and one-tap sharing with your insurer.

All generated automatically, minutes after the event, by a device that plugs into the OBD-II port in seconds.

The next time you hear "crash analysis" described as an abstract feature, you'll know exactly what it looks like: ten seconds of truth, measured as they happened. Here's hoping you never open one — but it's the kind of document worth having on your side before you find out what it costs not to.

Discover Guardian AI: mobisat.com/greenbox-guardian.html