This paper reports results from research conducted to analyse the extent of excess commuting in Dublin, Ireland. The research differs from similar studies on excess commuting in two ways. First, a disaggregate modal choice analysis of excess commuting is undertaken for two time periods – 1991 and 2001. Second, sensitivity analysis is undertaken to explore the impact of changes in the density of the transport network for users of public and private transport. The results suggest that excess commuting is considerably greater for users of private transport implying the greater inefficiency of commuting associated with that mode. By way of contrast, capacity utilisation measures suggest the opposite indicating the difficulty of using these measures for policy-making. The results suggest also that the greater inter-mixing of jobs–housing functions has facilitated reductions in actual commuting costs as well as increasing the range of available trip possibilities over the study period. In terms of the sensitivity analysis, the results suggest that public transport users could achieve dramatic savings on their commute if the density of that network was increased considerably.