Besides testing road materials for the public, blank forms for recording traffic will be supplied by the department to any one intending to build a road. When these forms are filled and returned to the laboratory, together with the samples of materials available for building the road, the traffic of the road will be rated in its proper group, as described above; each property of the materials will be tested and similarly rated according to its degree, the climatic conditions will be considered, and expert advice given as to the proper choice to be made.
[7] By Logan Waller Page, expert in charge of Road Material Laboratory, Division of Chemistry.
[8] This term is derived from the Swedish word _trappa_, meaning steps, and was originally applied to the crystallized basalts of the coast of Sweden, which much resemble steps in appearance. As now used by road builders, it embraces a large variety of igneous rocks, chiefly those of fine crystalline structure and of dark-blue, gray, and green colors. They are generally diabases, diorites, trachytes, and basalts.--PAGE.
As New Jersey contains a great variety of soils, there are many conditions to be met with in road construction. The northern part of the state is hilly, where we have clay, soft stone, hard stones, loose stones, quicksand, and marshes. In the eastern part of the state, particularly in the seashore sections, the roads are at their worst in summer in consequence of loose, dry sand, which sometimes drifts like snow. In west New Jersey, which comprises the southern end of the state, there is much loose, soft sand, considerable clay, marshes, and low lands not easily drained.
In addition to the condition of the soil, there is the economic condition to be considered. In the vicinity of large towns or cities, where there is heavy carting by reason of manufactories and produce marketing, it is necessary to have heavy, thick, substantial roads, while in more rural districts and along the seashore, where the travel is principally by light carriages, a lighter roadbed construction is preferred. In rural districts, where the roads are used for immediate neighborhood purposes, an inexpensive road is desirable. The main thoroughfares have to be constructed with a view to considerable increase of travel, as farmers in the outlying districts who formerly devoted their time to grazing of stock, raising of grain, etc., find it more profitable to change the mode of farming to that of truck raising, fruit growing, etc.