Despite the introduction of many instruments in the transport system, they failed to reach their target since gains in global environmental efficiency have not been enough to cope with the consequences of transport growth. The ultimate environmental challenge for transport policy makers is to improve the effectiveness of implementation of policy instruments. This paper explores the concept of multi-instrumentality as a systematic approach for transport policy integration and implementation. Based on extensive literature review, we assess a set of 14 transport policy instruments (weaknesses, strengths and barriers to implementation) and perform a pair-wise analysis of potential synergies in their integrated implementation. Conclusions are drawn on the potential success of multi-instrumentality.