Value for Money (VfM) has been used as a critical criterion for evaluating Public-Private Partnerships (PPPs), a popular procurement strategy for delivering transport infrastructure assets. However, there is a tendency for prevailing VfM techniques (e.g., Public Sector Comparator, PSC) to focus on obtaining cost savings rather than value per se. Despite the criticisms of the PSC and its alternatives for assessing VfM, there remains no research comparing decision-making methods for procuring transport infrastructure projects. In this instance, the upshot has been the public sector's inability to safeguard and deliver VfM to their taxpayers. Against this backdrop, we systematically review the VfM assessment literature to understand the effectiveness (e.g., strengths, weaknesses, opportunities, and threats) of prevailing approaches used to determine the ‘value’ of transport projects. In light of our review, we propose and introduce the concept of the ‘onion’ architecture to improve the decision-making practice of PPPs, which comprises four systematic future research directions and policy implications. To this end, our paper provides a platform for developing new procurement paradigms that can be used to future-proof transport infrastructure assets.