Around the Block: Urban Models with a Street Grid
研究以垂直和水平街道网格替代放射状街道的城市模型，发现改用网格仅改变标准模型中的一个参数，却显著改变人口分布和空间模式，说明解释密度和租金梯度的关键变量应是总交通成本而非到CBD的距离。
Models of urban residential structure usually assume that transportation costs are a function of straight-line distance from the central business district (CBD), which is equivalent to assuming an infinite number of radial streets. This paper presents and expands existing work on urban models with an alternative transportation system, namely a dense network of vertical and horizontal streets, that is, a street grid. Several models are examined, including some with a finite number of radial commuting arteries and one with a discrete suburban worksite. Switching to a Street grid alters only one parameter in the equations of a standard urban model, but alters urban population and leads to strikingly different spatial patterns. This last result implies that the appropriate explanatory variable for estimating density functions and rent gradients is not distance from the CBD but is instead total transportation cost.