530 COMMERCE YEARBOOK 
trucks have for the most part evolved a distinct field of transporta- 
tion—that of the short hauls and the small shipments which are not 
so profitable for the railways as other traffic, In many cases also 
motor trucks serve as feeders for the railroads. 
For further data as to automobiles and trucks see section on auto- 
motive products. 
INLAND WATERWAYS 
Aggregate River and Canal Transportation. 
The total tonnage carried via our inland waterways, including the 
navigable rivers and canals, without known duplication, aggregated 
approximately 173,190,000 tons in 1924. The tonnage passing 
through the Detroit River, connecting Lakes Huron and Erie was 
80,074,000 tons. Of this 8,036,460 tons was local traffic. The navi- 
gable rivers of the United States accounted for 102,430,000 tons of 
commerce, excluding through traffic of the Detroit River and all 
other known duplication of cargo. These figures may be compared 
with the volume of traffic by other channels of transportation (so far 
as possible eliminating duplication of tonnage via any one means of 
transport) as follows: 
Tonnage originating on railways. 
Overseas foreign cOMMEeree. oo mo cms 
Great Lakes trade, eliminating trade between the United States 
and Canada... _.____ mn 
Trade between United States and Canada via Great Lakes_____ 
United States coastwise ocean-borne commerce (excluding Great 
Lakes and Panama Canal)... .___. om 
Total of navigable rivers and canals (excluding all known dupli-~ 
cation) ___._-.-__. SE) AEH te ess mR A 
River transportation in the United States (excluding transit ton- 
nage of Detroit River)... _ ___.___. . 
Canal transportation in the United States__._. - 
Sault Ste. Marie. _._._._.. cer mmm cem—————a 
Panama Canal (intercoastal traffic only). _.____. 
1, 188, 000, 000 
82. 118. 000 
83, 292, 000" 
12, 930, 000 
67, 678, 000 
173, 190, 000 
102, 432, 000 
92, 290, 000 
72, 037, 000 
13. 527. 000 
Great Lakes to Ocean Waterway. 
The investigations of the Joint Engineering Board relative to the 
Great Lakes-St. Lawrence waterway were continued during 1925 
and are to be completed in 1926. The Board of Engineers for Rivers 
and Harbors (War Department) began investigations, also, regard- 
ing a Lakes-to-the-Hudson waterway. The Department of Com- 
merce inaugurated a survey of the principal economic questions in- 
volved in the Lakes-to-the-ocean waterway projects, which it is 
expected will be completed about the same time as the War Depart- 
ment engineering surveys.