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Above the Threshold

Every event exists because somebody chose a number

A harsh braking event is a threshold, a duration and a speed floor — three settings, usually vendor defaults tuned for a different vehicle. Fifty notes on the distance between what these systems measure and what people conclude from it.

All 50 notes

Folded by subject, with the first open. Everything is in the page rather than loaded on demand, so it prints and searches whole — though your browser may not open a fold to show a match, so expand what you want to scan.

What is measured 8 notes Every score is a weighted sum of event counts divided by exposure. Each of those three parts introduces a distortion, and the route usually dominates all of them.

Open Measurement →

Video 3 notes The direction the camera points determines the justification, the acceptance and the obligations. Four directions, four separate decisions.

Open Video →

Where the risk is 6 notes The strongest contributors are schedule, vehicle and exposure. Most of them are decided before anyone gets into a vehicle.

Open Risk →

Running the programme 13 notes Detection without a response is monitoring. The response is a conversation, and how it is conducted decides whether any of this works.

Open The programme →

Obligations 7 notes This is among the more intrusive things an employer does, and the paperwork is proportionate to that rather than to the cost of the hardware.

Open Obligations →

Buying 5 notes Start with three years of your own incident history. It frequently shows the problem is manoeuvring damage and new starters rather than harsh driving.

Open Buying →

The boundary 2 notes A behaviour system makes things possible that were not. Some of them should stay impossible.

Open The boundary →

Reference 6 notes The end state as a checklist, the questions this data cannot answer, and the four things that matter if nothing else is done.

Open Reference →

What this is

Fifty notes on driver behaviour monitoring, written for whoever has to deploy one, review the clips, or explain the numbers to the people they describe.

No vendor material, no product names, no sponsored content, no affiliate links.

Four things that hold

Every event exists because somebody chose a threshold, usually the vendor, usually tuned for a different vehicle. Set yours from a month of your own silent logging before anyone sees a score.

The route dominates the score. Swap two drivers' rounds for a fortnight and watch the scores swap with them. Two weeks settles an argument that otherwise runs for years.

A score you cannot explain cannot be defended — not to the driver, not to a representative, not to a tribunal.

The strongest safety measures are not behavioural. Vehicle assistance systems, schedule realism, fatigue in the rota and route design contribute more than anything a score measures.

Where to start

A system is being proposed: what actually predicts a collision.

The numbers are not trusted: thresholds, and whether the data is any good.

Cameras are being proposed: video systems, then the cab-facing note.

The goal is fewer collisions: the risk section, which is mostly not about driving.

What this is not

Not legal advice. Requirements on monitoring, consultation and video vary substantially by jurisdiction.

It does not describe how to enable live cab viewing quietly, how to present a proprietary score as validated, or how to use safety data for timekeeping. Those appear only in the notes about why they should not be done.

Independent software comparisons

Long-form shortlists for mobile driver teams, safety programmes, telematics and field operations.

To test how workforce records might sit beside driver-safety evidence, open the product homepage. For broader road-safety context, consult NHTSA's official site.