A file picture of a blue light brigade.
The Special Investigating Unit (SIU) is to investigate certain affairs of the national Department of Transport, provincial and municipal transport authorities, that perform functions in terms of the National Road Traffic Act. 

President Jacob Zuma signed an SIU proclamation on state transport institutions. 

It authorises the SIU to investi­gate allegations of unlawful or improper conduct related to the registration and licensing of motor vehicles; registration of vehicle ownership or licensing details; issuing of driving licences, learner’s licences or professional permits; conversion of foreign driving licences and military driving licences to driving licences; issuing of roadworthy certificates or issuing of operator fitness cards.