Commuting is an important part of the day for those who work placing a constraint on an individual's use of time. Recent years have seen an increase in time devoted to commuting; a trend which is not unique to the UK. There is much concern about the potential detrimental effect to health and well-being the burden of commuting imposes. This can be seen alongside a more general concern with levels of stress and psychological problems among the working population, which appear to arise from an ever-increasing demand on time and the problems of maintaining an appropriate work-life balance. There are a number of reasons why commuting might adversely affect health and well-being. For example, commuting is a cause of stress arising from its unpredictability and perceived loss of control leading to anxiety, raised blood pressure and musculoskeletal problems (Evans et al., 2002; Kolowsky et al., 1995); and can lead to boredom and social isolation (Gatersleben & Uzzell, 2007; Putnam, 2000). Some commentators, on the other hand, point to potential positive aspects of commuting, in providing time alone to work, read or think, or to simply wind down following work (Lyons et al., 2007; Ory and Mokhtarian, 2005; Redmond and Mokhtarian, 2001). Which of these potentially competing effects dominates is likely to be determined in part by mode of transport, the degree to which an individual has control over the journey and the time spent commuting. If commuting is the cause of lower well-being in the workforce, policy makers and employers should be concerned; not only because subjective well-being of the population may be a policy target in itself, but also because, as Bryson et al (2015) have shown, there is a clear positive relationship between worker well-being and firm productivity. Estimating the effect of CT on SWB, stripped of the influence of confounding factors, is important to appropriately inform policy. Establishing causality is however difficult, due to a variety of factors, that are largely unobserved by the researcher, such as individual and household preferences, determining both SWB and CT. Our work develops a method for establishing this causal effect based on observing shocks to commuting time due to either a relocation of place of employment or a change in transport infrastructure. Our aim is to establish (causally) whether, and if so, for whom commuting confers disutility through a loss in either SWB or health. The mechanisms that determine the differential H&SWB effects of CT across individuals will then be explored, with a particular focus on gender differences and intra-household decision making. For example, compared to men, women may place a higher valuation of time foregone when commuting due to greater family and childcare commitments. We will then seek to quantify in monetary terms the disutility individuals face from commuting. Given that commuting distance (and hence time) is often determined at the household level in conjunction with decisions over where to live and work, an important related question is whether the burden of commuting experienced by an individual is offset by gains in SWB of other household members. We aim to reconcile evidence on these research questions across two large and substantial household-based surveys. An important aspect of the research will involve translating the findings such that they are understandable to policy makers and others involved in debates around commuting, its effect on health and wellbeing and different modes of transport. We expect that that many of the emerging results will be of interest to the Department, in particular understanding differences in the burden of travel by gender and other groups and the valuation individuals place on commuting time. To this end we have an ongoing dialogue with the Department of Transport (see section on impact).