The Governor, in his discretion, may direct the commissioner of public safety, or his delegate, to inquire into such change of circumstances and report the same to him together with any recommendations he might have. The Governor, in his discretion, may order a new hearing on the matter before the Board of Public Safety or may, without hearing, issue his order directing the commissioner to grant a permit to such a county, municipality, college, or university to use speed detection devices. If a county, municipality, college, or university shall not be granted a permit to use such devices, it shall not apply for a rehearing until the expiration of six months.