An electronic logging device (ELD) is the device and software that record how long a truck driver has been behind the wheel, because American law limits how many hours a driver may drive each day. This page is set in the United States because that is where the product is mainly sold. In the United States, a driver may drive at most 11 hours in a day, within a window of 14 hours, and then must rest for 10 hours. This is called the hours-of-service rule. The ELD replaces the paper logbook, which drivers could fill in wrongly. Canada has a similar rule.
The ELD is wired to the truck's electronic control unit. It knows when the engine is running and when the truck moves. So it records driving time automatically, without the driver typing anything. The driver only chooses a status, such as on duty but not driving, resting in the sleeper berth, or off duty, for time when the truck is parked.
Here is a typical case. A truck driver is stopped at a roadside inspection station in Ohio. The inspector asks for the driver's record. The driver sends it from the ELD to the inspector's computer, and the inspector sees that the driver went over the 11-hour limit last Tuesday. The inspector can order the driver off the road until he has rested, and the trucking company can be fined. The same record can also protect the driver. It shows that a driver's late arrival was caused by a delay at the customer's warehouse and not by his own choice.
Why does the law exist? A tired driver is a danger to everyone on the road. Before ELDs, drivers wrote logbooks by hand, and many wrote false hours to deliver on time. Because the device reads the engine, the driver cannot change the driving time it records.
The Indian position is different. India has no law that requires an electronic logbook, and this product is not sold much here. Indian law does limit working hours for drivers in principle, under the Motor Vehicles Act, 1988, and the Occupational Safety, Health and Working Conditions Code, 2020. The Code came into force on 21 November 2025 and replaced the Motor Transport Workers Act, 1961. But the limits are checked mainly by inspection of paper records, and most trucks are run by small owners, many of whom drive themselves. Indian fleets worried about tired drivers use driver monitoring and AI dash cams, which watch the driver's eyes, and tracking boxes, which show where the truck is and how long it has been moving.
Hours worked are also useful to the company's workforce management and pay. The ELD sits inside fleet management software. The whole scene is fleet management.