Author: Jill McBeth
Date: February 29, 2024

What is a ELD? How does it work? and what do I need to know?

A ELD (electronic logging device) is a device that automatically records information using the CMV (commercial motor vehicle) ECM (Electronic Control Module), truck sensors and GPS trilateration to automatically record driving time. Fun fact, February is Black History Month and we need to acknowledge GPS was invented by mathematician Gladys West who was the second black woman to be hired to work as a programmer for the US Navy. As a CMV is moving the ELD is receiving information from the ECM and comparing that information to GPS position to monitor compliance to the Federal Hours of Service HOS (SOR/2005-313) and the Technical Standard. 

How does it work? 

A driver’s day in ELD sequence.  

  • When a CMV is powered, the ELD begins collecting data. 
  • The ELD must begin receiving power within one minute of the engine and must stay powered the entire time. 
  • A driver begins a shift by logging (authenticating) into the ELD device.
  • The ELD may be connected to the ECM via a wired connection or a Bluetooth connection. A driver using a Bluetooth connection would need to ensure the ELD is connected. 
  • When the CMV speed drops to 0 km/h for 3 seconds the ELD will automatically put the driver in on-duty status. Drivers only control off duty and sleeper-berth, driving and on-duty is automatically recorded and driving time cannot be changed. 
  • Throughout the day the ELD is monitoring the drivers time, location and the ELD functionality like connection, power and data transmission to the cloud.
  • The driver stops for fuel and a mandatory off duty period.
  • The driver pulls into the fuel island and when the vehicle stops for 3 seconds the ELD puts the driver in on-duty status. The driver finishes fueling and parks.
  • If the driver walks away and does not change the duty status to off duty the ELD will automatically put the driver in a on-duty status. 
  • Driver completes their workshift and logs off duty or sleeper berth.
  • The last entry of the day the driver certifies the RODS is correct and the motor carrier verifies the RODS. 
  • The motor carrier using the information from the ELD in conjunction with the driver to maintain continues compliance.

What information does an ELD record?

The ELD records all the required information from the Federal Hours of Service HOS (SOR/2005-313) and additional device compliance health monitoring in the Technical Standard. The data collected is related to: carrier identification, driver identification, vehicle identification, driver location information at prescribed intervals and each change of duty status, a running and cumulative odometer and engine hours total, duty status totals and ELD identification information. 

The drivers’ daily, workshift, cycle and off-duty requirements are continuously monitored, and a driver is alerted within 30 minutes of reaching a duty status limit. 

The ELD continuously monitors the device functionality and alerts the driver if any data is missing or there is a connectivity issue. Drivers are prompted to provide missing information if data is not automatically recorded. Drivers are alerted to uncertified RODS and missing data elements. Unidentified driving records must be accepted or rejected by the driver and no other information can be entered until unidentified driving time is resolved, Technical Standard 4.1.5 3).

The data from the ELD is shared between the drivers in-truck device and a dashboard or portal for the motor carrier to monitor the entire fleet. All the data is stored on the cloud for 6 months and can be retrieved by the carrier for inspection. The motor carrier is expected to monitor the drivers continuously using the information generated from the ELD. A driver should never be in a out of service condition for HOS because as soon as the driver is alerted to a problem the driver is supposed to immediately stop and alert the carrier. The driver and carrier are supposed to work together to resolve the issue and if the issue cannot be resolved follow the OOS criteria. The data doesn’t lie and the data doesn’t go away.