HIGHWAY BEIDGE LOCATION 6 
Plate 1, A and B, are typical of many instances of this kind. Unless 
this wing (fig. 1) is lengthened even more than shown, rip rap or 
some other form of bank protection is apt to be necessary at B. This 
is an element not only of added first cost, but of added maintenance 
cost as well. The channel change (shown dotted) might be a way 
out of the difficulty, but this is an item of added first cost and may 
or may not be cheaper than the skewed culvert and long wing. More- 
over, the channel change affects a natural watercourse and the 
builder at once becomes liable for any property damage resulting 
from overflow and erosion which may take place at C. 
All of the above undesirable features may be eliminated by adopting 
the revised alignment shown, and without introducing an added 
degree of curvature. This seems the logical way out of the diffi- 
culty but for the fact that the new alignment throws into the hill 
PROPOSED CROSSING 
, B ' 
'^RIPRAP' 
7 ^-s*%$ 
r^S) 
^55%, / 
^U 
SUBMITTED ALIGNMENT- 
DIRECTION OF ERODING 
CURRENTS AT FLOOD STAGE 
ft/ 
Fig. 1.— Small bridge structure as first located and relocation eliminating skew construction 
at D, thus involving more cutting and perhaps a more restricted 
sight distance around the curve. These last, then, are the considera- 
tions which must be balanced against the undesirable waterway 
features above enumerated. The solution will obviously depend 
upon the exact conditions disclosed by careful surveys and esti- 
mates along both lines, but the problem stated illustrates what 
may be encountered in the location of minor waterway structures. 
Each individual problem must, of course, be treated individually and 
solved on its merits. No fixed rules can be laid down, but the follow- 
ing points of merit and disadvantage may prove of assistance in 
studying any individual location problem. 
DESIRABLE FEATURES IN ALIGNMENT 
Maximum lengths of unbroken tangents. 
Maximum possible clear sight distance around hill points. 
Balanced earthwork quantities (cut and fill) . 
Minimum amount of overhaul. 
Location through material easily and cheaply handled. 
Minimum amount of rise and fall in grade line. 
Easy horizontal curvature. 
