highways, and the need for new facilities, we are indebted to the State-wide highway planning surveys of 46 States. These surveys have been made possible by the availability of joint Federal and State funds under the authority of the provision contained in the Federal highway legislation authorizing expenditure from several Federal highway appropriations and matching State funds for physical and economic investigations required for the planning of future highway projects and programs.
The information furnished by these surveys made it possible within the limited time available to select the six superhighways described in this report with reasonable assurance that the selection made is probably the best that can be made, and to obtain the substantial concurrence, in the particular selection, of the responsible State highway authorities of all States. In fullness and in accuracy the facts supplied for consideration in the investigation are unmatched by the information elsewhere or to any person available. In the absence of these facts this report would necessarily be far less definite in its conclusions, and less dependable in its authority.
CHARACTERISTICS OF HIGHWAY TRAFFIC SURVEYS DISCLOSED BY PLANNING
The facts derived from the highway planning surveys were especiallyuseful in disclosing the general characteristics of highway traffic, which have an important bearing upon the estimation of the amount of traffic that would probably use the proposed superhighways if they were constructed. Certain of these general characteristics that affect important decisions basic to the conclusions of this investigation will be described and illustrated by facts supplied mainly by the highway planning surveys of a number of States.
TRANSCONTINENTAL TRAVEL LIGHT
Some of the proposals for the construction of so-called transcontinental highways appear to be motivated by a belief that there exists an important volume of transcontinental travel; i. e., a through travel in motor vehicles between points in the Atlantic coast or far Eastern States and points in the Pacific coast or far Western States. No other explanation adequately accounts for the usual insistence upon a virtually absolute straightness of line between the continental termini.
Facts developed by the highway planning surveys definitely and conclusively show that there is no fully transcontinental travel, none even of semicontinental range, that could be accumulated in sufficient amount on any one or several highways traversing the breadth of the country, either to justify the construction, or to any considerable extent determine the character or location of such a highway or highways.
This conclusion is borne out by the planning survey facts presented graphically in plate 1. The greatest width of the tentacled central band shown in this graph represents to scale the average daily number of passenger cars traveling between points in the three Pacific-coast States and points in all States east of Idaho, Nevada, and Arizona, as actually counted at stations on all main-traveled east-west roads located approximately where such roads are crossed by the dashed line
144049°—39——2
