This paper presents an innovative 2 adult household mode choice model, which aims to capture the implicit trade-offs made by individuals and the household. Trade-offs with respect to vehicle allocation and joint travel opportunities are examined. This understanding is achieved through the examination of the choice of mode pairs at the household level rather than examining individual choices separately. The modelling exercise focuses on the morning peak period mode choice for two adult households who may be auto-sufficient or auto-deficient. The presented models are developed using a traditional household travel survey, which does not explicitly explain the trade-offs made at the household level. To capture these trade-offs, the survey data is processed to capture individual travel times increases and household travel cost saving that are available to households who engage in joint travel. It was found that auto deficient households were far more likely to travel jointly. Furthermore, the angle between each household members destination is found to be relevant to predicting the propensity for joint travel. The implications of these issues on several different travel demand management polices is also briefly discussed.