Transport Audit Directorate is one of the seventeen (17) audit directorates under the Office of the Comptroller and Auditor General of Bangladesh. The mandate of this directorate is to carry out audit of four ministries/divisions namely Ministry of Railways, Road Transport and Highways Division, Bridges Division and Ministry of Shipping, their subordinate offices and extra-budgetary organizations under these ministries/divisions. This directorate, along with two regional offices in Chattogram and Rajshahi, is particularly assigned to audit of State Owned Enterprises including Bangladesh Railway, Bangladesh Road Transport Corporation (BRTC) and Bangladesh Inland Water Transport Corporation (BIWTC). Some autonomous bodies including Bangladesh Road Transport Authority (BRTA), Dhaka Transport Coordination Authority (DTCA), Bangladesh Bridges Authority and Bangladesh Inland Water Transport Authority (BIWTA), and  so on are also under jurisdiction of this audit directorate. The objective of this directorate is to conduct effective audit of the aforementioned offices in order to ensure value for public money and provide reliable and objective information to the stakeholders with a view to establishing transparency and accountability in their activities.

Audit observations involving Serious Financial Irregularities (SFI) are initially developed into Advance Paras (AP) and subsequently Draft Paras (DP) after taking into consideration the replies received from the concerned entities and the Principal Accounting Officer (Secretary to the Ministry/Division). With the approval of Comptroller and Auditor General of Bangladesh DPs are then incorporated in the audit reports. In addition to conducting traditional ISSAI-compliant financial and regularity audits, this directorate also carries out ISSAI-based performance audit to evaluate economy, efficiency and effectiveness in the management of public resources, thereby contributing to governance. Furthermore, nowadays, this directorate is carrying out grants and appropriation based audit with the objective of facilitating optimum utilization of national budget.