LAND SUBDIVISION 281 



of traffic relations but also of the use of the land for residential, commer- 

 cial, or manufacturing purposes. The intermingling of widely different 

 types of use is likely to be inefficient from the point of view of any one 

 type or from the point of view of all together. The spread of manu- 

 facturing or commercial activities into residential districts, or the spread 

 of a lower class of residential development into an area occupied by a 

 : higher class, destroys a great deal of present value and is likely to find 

 the ground unsuited by its design to its new use. Recognition of the 

 advantages to the whole community secured through control by the 

 public, under the police power, of the uses of private property has 

 brought about our zoning ordinances and our regulations governing the 

 subdivision of unplatted land. Nearly all our largest cities and many 

 small towns have by zoning undertaken the guidance of future uses of 

 land, and a considerable number have major street plans into which the 

 lay-out of new subdivisions must be adjusted.* Where such regulations 

 exist, they are first to be consulted by the land developer ; where they 

 do not, he must make the best prophecy he can himself as to the future 

 use of the land and proceed accordingly. The developer must then 

 consider what is to be the social and financial status of his future 

 purchasers, roughly, that is, the price they are willing to pay for a 

 building lot. If the land subdivision scheme is large, it may be different 

 in different parts in this regard, but in any one small neighborhood 

 : widely different residential types will not mix and the cheaper will drive 

 out the more expensive. Having made these decisions, and taking into 

 account the original cost of the land per square foot, it will be possible for 

 the land developer to determine roughly the selling price per square foot 

 and the range of lot sizes which would be most desirable in the sub- 

 division. With this in mind the road locations are to be studied and so 

 chosen that with the least amount of road and the greatest traffic con- 

 venience, the land may be all divided into lots of the chosen range of size. 

 Evidently the size of a lot as well as the topographic and traffic consider- 

 ations will motive the determination of the distance from one road to the 

 next. Within certain limits the shape of the lot may be varied to give the 



* Cf. discussion of municipal regulations controlling land subdivision, p. 293-294. 



