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IDR Analysis

Data recorders store a wide range of valuable information, essential to reconstruction work.

Incident Data | Mix Telematics | RSG | XDR | INCA

Incident and Journey Analysis

Many police cars, ambulances, fire appliances and a few private vehicles are fitted with data recorders, generally referred to as IDR’s [Incident Data Recorders], JDR’s [Journey Data Recorders] or EDR’s [Evidence Data Recorders].

Whatever the name, they serve one of two purposes, to record incidents [accidents and periods of harsh driving] or journey’s, some will record both.

Some data will be retained in the device until downloaded by a trained person or automatically transferred to a computer server on return to base or via GPRS [mobile phone] technology.

We can offer a full data analysis with a court ready expert report, this will be accompanied by exhibited graphics and maps where appropriate. This is a service of use to police, ambulance and fire services, and other users of the data loggers, or solicitors representing drivers at criminal or misconduct hearings.

Similarly those representing clients that have been involved in an incident with a vehicle fitted with one of these devices may well require the data to be checked prior to civil proceedings.

Our principal consultant, Jonathan Webb, is not only trained to advanced level and very experienced in analysing this data he also has the background of being an accident investigator and trained to advanced driving standards with further experience of driving a whole range of emergency vehicles from police, fire and ambulance services.

Jonathan is regularly instructed in this field and remains up-to-date with the latest software and techniques.

Mix Telematics / Siemens

Their devices were previously branded as Siemens and VDO/Siemens. The data they produce is analysed using the UDScience program. Others have been known to attempt the analysis using prints from the software, these have proven to be very inaccurate. They have limited journey information, and are targeted at accident analysis. The device records 45 seconds of data per incident and can store 12 incidents. It can log:

  • Vehicle speed
  • Longitudinal and transverse acceleration
  • Direction (compass point)
  • Distance travelled
  • Status of electrical components (as specified at installation) normally including:
    • Ignition
    • Brakes (from brake lights)
    • Indicators
    • Lights
    • Emergency equipment if fitted

CompassAI is licensed to use this software.


These devices have the advantage of being a modular design, and as such can include full accident analysis storing in the order of 20 x 1 second incidents where the following is logged:

  • Vehicle speed
  • Engine revolutions [per minute]
  • Longitudinal, lateral and z-axis acceleration
  • Direction [compass point]
  • Distance travelled
  • Status of electrical components (as specified at installation) typically
    • Ignition
    • Brake application [from the brake pedal]
    • Hand brake application [from the hand brake lever]
    • Indicators
    • Lights
    • Seat belt usage
    • Emergency equipment if fitted

Additional modules can include vehicle location [from the Global Position System, subject to coverage] and are other features including driver identification. If the data is uploaded to a central server it can be used for a range fleet management uses.

CompassAI is licensed to analyse this data.


These devices, created by APD Communications, are fitted to a range of emergency services vehicles, primarily emergency response police vehicles. As part of their Artemis suite for vehicle fleet tracking and management this device combines the latest Journey / Incident Data Recorders allowing vehicle tracking and subsequent analysis.

Of use within accident investigation the XDR device records second by second journey data including:

  • Date / Time
  • Location [from GPS]
  • Speed [2 sources]
  • Direction
  • Driver ID
  • Acceleration in 3 planes 
  • Roll, pitch and yaw
  • Lights and other analogue inputs as specified

and for 45 seconds the rate of recording is increased to 100 Hz [100 records per second] when an accident is detected. For accident investigation purposes this data is analysed using the Artemis CDA program. CompassAI is licensed to use this software.

Inca (1&2)

These devices, by APD Communications, are fitted to a range of emergency services vehicles.

The have limited functionality and are not designed for collision investigation purposes. However, they do log the following [configurable] data:

  • Date
  • Time (hours, minutes and seconds)
  • Latitude (in degrees and decimal minutes)
  • Longitude (in degrees and decimal minutes)
  • Speed (in kilometres per hour)
  • Bearing (in degrees from north)
  • Up to 8 inputs for lights, sirens and  so on;

… and as such they can be used to provide journey and approach speeds, but that speed will be useful as a guide only.

CompassAI have developed a method of displaying this data [obtained in a CSV format] on a map, suitable for court purposes.

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