As part of the resolution, the settlement agreement has a duration of one year, though there is potential for an extension at the NHTSA's discretion. Since the investigation's initiation, Zipcar has made significant strides according to the federal regulator. Thanks in part to an automated documentation system for recalled vehicles, the company has been credited for its improved handling of recall procedures. Zipcar isn't the only rental operator to come under the NHTSA's watchful eye. Last December, the NHTSA announced an investigation into Hertz, probing if the company rented out cars with unaddressed recalls.