Yes, it is permissible to select alternates. However, it is only permissible if the primary driver selected will not be available for testing during the selection period because of long-term absence due to layoff, illness, injury, vacation or other circumstances. In the event the initial driver selected is not available for testing, the employer and/or C/TPA must document the reason why an alternate driver was tested. The documentation must be maintained and readily available when requested by the Secretary of Transportation, any DOT agency, or any State or local officials with regulatory authority over the employer or any of its drivers.