The Samsara Vehicle Gateway (VG) detects harsh events, such as harsh brakes, accelerations, turns, and crashes. After installation, Samsara assigns harsh event thresholds based on the detected vehicle type, with configurable sensitivity levels for harsh acceleration, braking, and turning per vehicle type. Each harsh event surfaces in Harsh Event Reports and for Reviewing Safety Events in the Safety Inbox.
To raise a harsh event in the Samsara dashboard, the following minimum criteria must be met:
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The vehicle is on a trip.
A trip is defined as traveling from a starting point to a stop or destination. By default, a trip begins when your vehicle achieves a speed of at least 5 mph and ends when the vehicle speed remains below 5 mph / 8 km/h for 5 minutes or when your vehicle crosses a state or national border.
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The VG detects an event with a g-force above the configured threshold.
Event detection uses oriented acceleration data when the device is calibrated. For details about harsh event types and thresholds, see Harsh Event Types and Thresholds.
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The safety event has met the minimum safety event criteria.
For safety event criteria, see Reviewing Safety Events in the Safety Inbox.
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The safety event video is available to review.
For video retrieval limitations and considerations, see Video Retrieval Process.
To get started with Harsh Event Detection, review the following workflows to optimize its use and customize it for your fleet:
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Review Event Detection Best Practices: For the most accurate Harsh Event Detection, review the Harsh Event Best Practices.
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Customize Event Detection: Samsara automatically applies recommend settings based on the detected vehicle type. To customize the vehicle type and configure detection sensitivity for harsh acceleration, braking, and turning thresholds, see Configure Harsh Event Settings.
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Set alerts: In addition to in-cab audio alerts for drivers, you can also configure an alert to receive an email notification or an SMS when a harsh event occurs.
For the most accurate harsh event detection that's appropriate for your fleet, Samsara recommends that you:
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Ensure the VG is securely installed in a location where the device is unlikely to be disturbed by the driver. For example, if the VG is loosely installed or kicked by the driver this could interfere with detection or generate a false harsh event.
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Only relocate the device if necessary. The VG re-calibrates after the device detects movement to its position.
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Select an appropriate Trip Activity threshold for your fleet.
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Verify device calibration status is
Calibratedfrom the Gateways report. For proper calibration, ensure the vehicle has adequate drive time with varied driving styles including braking, accelerating, and turning. If your Device Calibration Status is notCalibrated, see Calibration Status Types.
The calibration process can take up to a few hours and is dependent on the gateway health, driving behavior and duration, and a successful installation. Harsh event detection begins only after calibration is complete.
The gateway device list (Settings ( ) > Devices > Gateways) indicates one of the following Device Calibration Status for your VG:
|
VG Health Status |
Description |
Recommended Action |
|---|---|---|
|
N/A |
Device does not require calibration for detection. |
— |
|
Pending |
Device is updating to enable calibration. |
Ensure that the device is powered on and allow up to two hours for the update process to complete. |
|
Not Calibrated |
Calibration process has not yet started. |
Ensure the vehicle is active and review the Best Practices to ensure successful calibration. |
|
Calibrating |
Calibration is in process. |
Review the Best Practices to ensure successful calibration. |
|
Calibrated |
Calibration is complete. |
— |
The VG automatically detects the vehicle type and assigns harsh event thresholds. You can influence the volume of events that the VG surfaces to the Samsara dashboard by modifying the default sensitivity settings. These settings can be modified for all vehicles in your fleet or for selected vehicles.
To configure settings to selected vehicles, see Safety Settings for Individual Vehicles or use the following workflow to configure settings to all vehicles in your fleet:
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Select the Settings icon (
) at the bottom of your Fleet menu to view dashboard settings.
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From within the Fleet settings, select Safety > Harsh Events.
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Select the default Vehicle Type for vehicles in your fleet (Automatic, Passenger Car, Light Truck, Heavy Duty).
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Adjust the Harsh Event Sensitivity settings for each harsh event category (Harsh Acceleration, Harsh Brake, Harsh Turn) according to your dash cam model:
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Save to confirm the settings.
Samsara recommends that you monitor the event volume using the recommended default Normal settings for 1-2 active weeks before adjusting the thresholds. Increasing to a High sensitivity setting may increase the volume of harsh events detected. Conversely, decreasing to a Low setting may decrease the volume of harsh events detected.
Harsh acceleration, brake, and turn events that occur at speeds of less than 5 mph are automatically filtered out of the Safety Inbox.
Samsara recommends that you Use Recommended Settings and monitor the event volume for 1-2 active weeks before adjusting the thresholds.
When you enable Advanced Options, you can configure the sensitivity settings for each vehicle type. You can adjust the sensitivity from OFF (no events) to MAX for each harsh event category and vehicle type.
Harsh event detection settings are configured per vehicle type and event type. Customers can select sensitivity levels—High, Normal, or Low—for harsh acceleration, braking, and turning. The VG's built-in accelerometer detects g-forces to gauge the severity of a harsh event, relative to the vehicle. For example, harsh brake and harsh turn events are calculated differently for a passenger vehicle as opposed to a heavy duty vehicle.
The higher the sensitivity level that you set when you Configure Harsh Event Settings, the lower the g-force threshold to trigger an event. The g-forces for each sensitivity level vary by vehicle type. The following list summarizes the harsh event types:
The VG uses calibrated, vehicle-oriented sensor data to detect harsh events. To improve accuracy and reduce false positives, harsh acceleration events that occur at very low speeds may be filtered and not generated.
When multiple events occur at the same time, the VG determines which event to surface based on event type and severity. The following logic applies:
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If a crash and one or more harsh events are detected at the same time, only the crash event is surfaced in the dashboard.
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If multiple harsh events occur simultaneously, the event with the highest g-force is surfaced.
Sensitivity levels control how easily events are triggered based on g-force thresholds. Higher sensitivity triggers more events; lower sensitivity reduces detection frequency. The table below summarizes this relationship:
|
Sensitivity Level |
Detection Behavior |
|---|---|
|
High |
Triggers at lower g-forces (more events) |
|
Normal |
Balanced detection |
|
Low |
Triggers at higher g-forces (fewer events) |
Each harsh event type is associated with specific trigger conditions and video behavior. The list below summarizes how each event is detected and handled:
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Crashes: Triggered only by driving events that exceed 2.0g, regardless of vehicle type. Each crash event surfaces a 30-second video to the Safety Inbox. Other crash forces do not automatically generate a safety event; however, if the vehicle was on a trip, you can request a a video retrieval in order to Manually Generate a Crash Event.
Common scenarios that may appear as crash events include:
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Low impact events: Low-speed impacts such as parking lot collisions or sideswipes may not exceed 2.0g and therefore may not trigger a crash event.
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False positive crashes: High g-force events not caused by crashes—such as a kicked VG, pothole, or reverse hookup—may still be surfaced as crashes.
Crash events that meet the detection threshold may be dismissed after they surface, depending on additional filtering. Events that are determined to be false positives are automatically moved to the Dismissed folder unless a user has already changed the event status.
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Harsh acceleration: Triggers a 10-second video when the g-force threshold is exceeded. Events that occur at very low speeds may be filtered and not generated.
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Harsh brake: Triggers a 10-second video when the g-force threshold is exceeded. A Very Low sensitivity level is recommended only for fleets with vehicles that produce frequent braking events, such as dumpster trucks or construction vehicles.
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Harsh turn: Triggers a 10-second video when the g-force threshold is exceeded.
Comments
1 comment
Samsara took a huge step backwards by dumbing down the g-force thresholds for harsh turn and harsh brake events on the newer camera models. As you can see on this page, the older cameras (CM11/CM12/CM22) still allow the user to fine tune the g-force required to trigger an alert using a high-granularity slider. This fine tuning was available for the newer cameras (CM3x) until Samsara took this functionality away, replacing it with a dumbed down four step configuration (Very Low, Low, Normal, High) for Harsh Turns and Harsh Brakes and a three step configuration (Low, Normal, High) for Harsh Acceleration, each with pre-configured thresholds chosen by Samsara. My company had taken time to fine tune these settings using the previously available slider to generate an alert volume appropriate for our specific needs; we no longer have that ability. Again... huge step backwards and I don't understand why Samsara would remove the ability to fine tune settings.
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