Traffic concepts

Roads

This API returns speed and traffic metrics for either the selected corridor or all road segments in the zone provided. The API will be in Corridor Mode if the road segment parameter is filled and the zones parameter is empty, otherwise, the API will be in Zone Mode.

Spot speed metrics are measured as the highest speed achieved by the vehicle while traveling on the road segment.

Free-flow speed is taken from the 85-percentile spot speed aggregated across the last month in the date range provided, up to the last complete calendar month.

There are several metrics that depend on Free-flow speed:

• FreeFlowSpeed

• SpotSpeedPctOfFreeflow

• TravelSpeedPctOfFreeflow

• TravelTimeDelayFromFreeflow

These metrics will be NULL if Free-flow speed is not available. This can occur for roads less than 1 month old, or roads that have been assigned new segment Ids due to an OSM change or changes to its geometry.

Harsh Events (Beta)

Harsh event detection rules are currently threshold-based: The first step to GPS-based harsh events detection is to calculate the rate of change of the velocity (acceleration/deceleration) of the vehicle. If a vehicle’s rate of change in acceleration exceeds the set threshold for the event type, a harsh event is registered.

Harsh events are divided into three types: Harsh Acceleration, Harsh Braking and Harsh Cornering. Detecting and capturing harsh events allows us to measure the risks of drivers/vehicles and roadways.

Provide an API that monitors harsh events (harsh braking, harsh acceleration, harsh cornering) down to the road segment and provides filters by vocation, industry, and vehicle class.

GPS-based Acceleration

The first step to GPS-based harsh events detection is to calculate acceleration /deceleration of the vehicle. We use the following time series signals:

• Timestamp

• Latitude

• Longitude

• Speed

• Ignition

Note:

Harsh events are identified starting on March 1, 2021. Data prior to this date is not available.