本文以高速公路交流道特定區為案例，以現況人口數與現況土地開闢面積為應變數，建立一個包含兩條聯立方程式的模型，並利用二階段最小平方法估計此模型的相關參數，藉以探討高速公路交流道特定區發展過程中，人口成長與土地開發兩者之因果關係。實證結果發現，交流道特定區現況土地開闢面積對特定區現況人口數具正向且顯著的影響關係，並存在現況土地開闢面積為因；現況人口數為果之因果關係。對於特定區內不同土地使用分區之開闢面積對現況人口數的影響程度不同。整體而言，高速公路交流道特定區由於具有鄰近高速公路的優越區位，因此，土地開發能夠吸引人口及產業進入。其他公共建設是否均具有此種效果應個別加以研究。

Highway Interchange Special Districts (HISD) are planned to facilitate the benefits of having a location proximate to a freeway. The development of HISD may follow two different paths. One is that land is supplied first and population comes in. The other is that people swarms into the districts first and land development follows to alleviate the pressure of physical aspects. A model of two simultaneous equations is used to determine what path is adopted. The independent variable for each of them is population and land use acreages. The two-stage-least-squares technique is employed to estimate the parameters. The model shows that population has positive and significant effect on land use acreage, and vice versa. On the whole, land use development is the cause and then population growth occurs in those districts.