Abstract
This article is a primary-theoretical research that investigates the effect of urban spatial structure on commuting patterns. The examined variables are the city size, centrality, concentrations of activities, urban densities, and land-uses distribution. The selection is based on the most commonly used variables in the literature. The objective is detecting the prior theoretical and empirical contributions from the old and recent studies to conclude the research gap for potential optimization. The prior research confirms that both city size and the distance from the Central Business District are positively led to longer commuting distance, time, and cost. On the contrary, most of the literature has substantiated that the decentralized and densified population, employment, and social services, as well as the mixed land-uses, would notably reduce the average commuting distance, the number of motorized trips, and total vehicles miles travelled. The effect of urban-density and land-uses mix remains unclear due to findings that conflict with the empirical results. In the high-densified and diversified districts, traffic congestions may result in longer commuting time, which offsets the decrease in the distance. Furthermore, there is a research gap detected on the effect of the spatial distribution of urban densities, concentrations, and land-uses on the commuting patterns in scale of a city. Finally, this article raises the motivation to empirically investigate these variables in further studies for the Egyptian case.