Pittsburgh Main Thoroughfares and the Down Town District / Improvements Necessary to Meet the City's Present and Future Needs

by Frederick Law Olmsted

Objects To Be Secured

In outline the objects to be secured are these: (a) An accurate framework of reference points needs to be established, including: 1. The gradual systematic setting of permanent street monuments throughout the city to serve as reference points for the definite determination of street locations and for all public and private local surveys. 2. The accurate determination of the locations and elevations of these and other monuments and bench marks in reference to a single general system of coördinates and in reference to the United States Government bench. 3. As a means of accomplishing these ends, an accurate geodetic triangulation of the district, supplemented by the necessary precise traverse work and precise leveling, all fully checked and compensated for errors.

(b) The existing local surveys and records need to be tied into the accurate framework thus established, and in cases which show deficiencies or discrepancies beyond a reasonable and carefully defined standard of accuracy, they need to be gradually, in due turn, re-surveyed and re-plotted.

(c) Complete topographical maps, based upon the framework first described, should be prepared upon some uniform system beginning in those sections where public works are immediately contemplated and gradually extended so as to cover the whole area into which the city's growth is likely to spread.

In the facts which would be gathered in the above process, and only in such facts, can a safe basis be found for plans that will provide the most economical and effective layout of new streets, sewers, parks, water system—in short for a city plan that will minimize the total draft on the taxpayers for public works and give the maximum results for money expended.

Technical Procedure

The actual steps of technical procedure called for, in addition to the present routine work of the Bureau of Surveys, appear to be about as listed below. I omit at this point any consideration of the method of deciding on the plans for future improvements—the city planning proper, which would be based on the surveys—or of the procedure for enforcing any part of a city plan when adopted, and consider only the work of recording and mapping.

The steps that are mentioned last are more or less dependent upon those mentioned first, for any given area of the city, but the several steps of the work would be carried on more or less simultaneously, and some of the results would become available for use at once. 1. The establishment of reference points by triangulation and precise traversing and leveling throughout the district, and the reduction of these points to a general coördinate system. 2. The surveying, in relation to the new coördinate system, of existing street monuments and reference points, and of existing buildings, fences, bound-stones, and other evidences of ownership; and the preparation of general topographical maps. 3. The determination of the correct location of the legal boundaries of streets and public properties, and the translation of the old descriptions, running lines, etc., into terms of correct descriptions related to the new coördinate system. 4. The verification or correction of the legally established street profiles in terms consistent with the real distances and levels. 5. The setting of additional street monuments. 6. The draughting and publication of maps.

Maps

The maps might ultimately include the following features, every one of which is to be found in the maps of one or another of the progressive cities of this country and Europe, and many of them in all.