UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1486 
Washington, D. C. 
April, 1927 
HIGHWAY BRIDGE LOCATION 
By C. B. McCullough, Bridge Engineer, Oregon State Highway Commission, 
in Cooperation with Bureau of Public Roads, United States Department of 
Agriculture 
CONTENTS 
Page 
Introduction .- . 1 
Location of minor structures 2 
Desirable features in alignment 3 
Undesirable features in alignment. 4 
Desirable features in culvert location 4 
Undesirable features in culvert location 4 
Cost considerations involved in the location of 
large structures 4 
Length of crossing 4 
Angle of crossing 5 
Foundation conditions 6 
Permanency of channel 12 
Maintenance considerations affecting bridge 
location 13 
Scour around piers 13 
Shifting or lateral movement of channel ... 14 
Effect of ice and drift 18 
Alignment considerations 20 
Page 
Grade-line treatments 21 
Horizontal alignment _. 25 
Structures on curves 25 
Traffic influence on bridge location 26 
Through traffic considerations 26 
Regional traffic considerations 27 
Local traffic considerations 27 
Location over navigable waters 27 
Direction and velocity of currents, cross 
currents, tidal flows, etc., as affecting the 
horizontal clearance required 29 
Wind conditions as 'affecting horizontal 
clearance required 31 
Alignment of stream or waterway as affect- 
ing sight distance for navigation 31 
Dock and wharf rights at the bridge head.. 31 
Anchorage above the bridge site 31 
Constriction of waterway by filled ap- 
proaches 31 
INTRODUCTION 
Bridge engineers have felt the need for a publication setting forth 
important principles governing bridge location, foundation investi- 
gations, and selection of type. Standard textbooks are satisfactorj^ 
as to the structural design of bridges, but have been lacking on the 
above points. This bulletin deals with the first of these subjects and 
is the result of cooperative work between the Bureau of Public Roads 
of the United States Department of Agriculture and the Oregon 
State Highway Commission in Federal-aid road construction. 
With the inception of any bridge project, the first duty of the 
bridge engineer is to investigate the site and to select the most eco- 
nomical crossing consistent with certain standards of quality as 
regards maintenance and operating conditions. It frequently hap- 
pens, however, that the particular location which combines the above 
features to maximum advantage does not combine advantageously 
with the improvement project viewed as a whole. Some sacrifice 
in the selection of the bridge crossing is, therefore, necessary in order 
that it may more completely fit into the general location scheme. 
32903°— 27- 
