The purpose of screening disembarking passengers is to identify and segregate persons not in possession of passports or travel documents from the normal flow of passengers. In addition, inadmissible travellers who may pose a risk or who are otherwise inadmissible can be identified through intelligence-based indicators such as identified trends, lookouts and Advanced Passenger Information/Passenger Name Record (API/PNR) information received from Passenger Analysis Units (PAU).

Disembarkation screening also enables an officer to identify which airline has carried an improperly documented passenger to Canada and ensures that the CBSA can levy administration fees and removal costs against a liable transporter. When two international flights arrive within a brief period of time, for example, passengers from each flight may intermingle at the Primary Inspection Line (PIL). This can make it difficult to determine which carrier brought an improperly documented passenger to Canada and to properly
assess liability.

On-board inspections, disembarkation screening, pre-PIL roving and post-PIL activities are part of the examination continuum. At these preliminary checks, the DART officer does not do a full examination and does not make a decision to authorize or deny entry. Instead, the officer verifies that a passenger has the necessary documentation and refers undocumented and suspected inadmissible persons to Immigration Secondary for an indepth examination. This does not usurp the authority of PIL as DART referrals do not bypass PIL.