wheelbasedvehiclespeedj1939 - SPN 1862

The speed the vehicle is traveling based on wheel rotational speed

High-Level Explanation

This signal is an estimate of the vehicle's speed based on the speed at which the wheels are rotating. This signal assumes a radius of the wheel and then calculates longitudinal speed based on the revolutions of the wheel per minute using the following, where s is the revolutions per minute of the wheel and r is the radius of the wheel in meters:

$$v = r\cdot s \cdot \frac{2\cdot\pi \cdot (\frac{radians}{revolution})}{60 \frac{seconds}{minute}}$$

For at least two example vehicles, this speed is misreported as 255.996094 kilometers per hour, which is not plausible for a vehicle. These are possibly error states for the signal and must be removed for the values to be useful. This can be done by:

idxs = gdf.loc[gdf['wheelbasedvehiclespeedj1939'] > 255].index
gdf.loc[idxs, 'wheelbasedvehiclespeedj1939'] = np.nan

Additionally, to convert this signal from kilometers per hour to miles per hour, one can multiply by 0.621371 to convert, as in

gdf['wheelbasedvehiclespeedj1939_mph'] =  gdf['wheelbasedvehiclespeedj1939']*0.621371

Enables

Traffic and average road speed, correspondingly with

Enabled By

Known Quirks

Visualizations with Explanations

Original wheelbasedvehiclespeedj1939 signal values

Cleaned wheelbasedvehiclespeedj1939 signal values

A set of wheelbasedvehiclespeedj1939 values during a small portion of vehicle operation