One of the most promising approaches to mitigating land-use and transportation problems is continued research on urban commuting. Commuting is essential to many individuals, allowing them to participate in the labour market and earn a living to meet their essential needs. As such, a better understanding of the determinants of commuting will ultimately lead to a better understanding of the complexities of employment, housing, and the many spatial processes underlying commuting. However, in order to understand the commuting process, it is important to examine the milieu within which commuting takes place: the local labour market (LLM). In this thesis, the interplay between commuting and LLMs is explored through the use of regionalisation techniques and spatial interaction models. It is shown that LLM characteristics play a significant role in intra-regional commuting patterns and that a failure to account for LLM conditions may seriously hinder the applicability of models of commuting. Specically, it is found that there are many dierent LLMs across Ireland, and that these LLMs characterise the commuting patterns of population sub-groups. By incorporating these LLMs into models of commuting, this thesis shows that in addition to distance and working population size, the spatial structure of origins and destinations and a number of non-spatial attributes such as unemployment, housing density, and education, all signi- cantly aect commuting ows. Furthermore, the distance decay component of these models appears to be capturing a combination of geographical distance and regional dierentiation due to LLM boundaries, leading to `functional' distance decay. This concept of functional distance decay is a key nding of this thesis, and indicates that in addition to the conguration of origins and destinations, distance decay is also dependent on the spatial structure of LLMs, or more generally, the totality of surrounding conditions within which spatial interaction takes place.