ELD stands for Electronic Logging Device. It is DOT-certified electronic hardware that connects to the vehicle's engine to record driving hours. It includes a screen for the driver so they can monitor their current status as well as the ability to print hour logs when required by DOT inspectors.
ELDs connected to a fleet management software can transmit real-time driving logs to a back-office system.
In the past, ELDs have been referred to as AOBRDs (Automatic On-board Recorders) and EOBRs (Electronic On-board Recorders). Despite slight variations, the central function of all these devices is to electronically record a driver’s activity to log HOS (Hours of Service), also known as RODS (Record of Driver Status).
For an ELD to be used to record HOS it must be DOT-certified. The new ELD Mandate (due to be published October 30, 2015) will specify new requirements for ELD hardware. The ELD Mandate will require that all commercial vehicles will need to have an ELD fitted to replace the current paper log book system.