49 CFR §395.32

1. (a)Tracking non-authenticated operation. The ELD must associate the non-authenticated operation of a commercial motor vehicle with a single account labeled “Unidentified Driver” as soon as the vehicle is in motion, if no driver has logged into the ELD.
2. (b)Driver. When a driver logs into an ELD, the driver must review any unassigned driving time when prompted by the ELD and must:
   1. (1)Assume any records that belong to the driver under the driver's account; or
   2. (2)Indicate that the records are not attributable to the driver.
3. (c)Motor carrier.
   1. (1)A motor carrier must ensure that records of unidentified driving are reviewed and must:
      1. (i)Annotate the record, explaining why the time is unassigned; or
      2. (ii)Assign the record to the appropriate driver to correctly reflect the driver's hours of service.
   2. (2)A motor carrier must retain unidentified driving records for each ELD for a minimum of 6 months from the date of receipt.
   3. (3)During a safety inspection, audit or investigation by an authorized safety official, a motor carrier must make available unidentified driving records from the ELD corresponding to the time period for which ELD records are required.