The Meridian times. (Meridian, Idaho) 1909-1938, 1917-06-08


aside from proper drainage, may be to
determine a reasonable balance be-
tween the desire to avoid unnecessary
damage to farming land and the pur-
pose to secure a reasonably direct
route over good ground.
One of the most common problems in
laying out road In level country is to
decide between continuing a circuitous
route around cultivated fields or along
rectangular land lines, and establish
ing new diagonal route across the
| fields.
In mountainous regions, on the other
hand, the problem may be to fit the
/ road to the contour of the country, re-
CARELESS of land lines, cultivated fields.
and all other considerations except
grade, drainage and line.
In general, the proper location and
design of road involves: a. deter
mining its controlling points; that ia.
fixing it's general route with referen.Ae
to certain points which the road must
pass through, (2) surveying a route
| which passes through the controlling
| points and is otherwise adapted to the
lay of the land, (3) study of the
drainage situation, az preparing such
plans and drawings as are necessary
for proper construction and a COM
plete record.
Controlling Points.
Such features of the locality as gaps
| through ridges, exposure to the sun,
narrow stream crossings, and suitable
points for crossing railroads (prefera-
bly, by means of overhead bridges or
under passes), together with the ne
cessity for connecting up with certain
centers of population, usually will
serve to fix the location of a road with
in fairly definite limits. For impor-
tant roads these controlling points are
determined by careful inspection of all
possible routes.
The Survey.
The care which should be exercised
in making road survey necessarily
must depend upon the Importance OF
. the road and the amount to be expend
ed in its Improvement. An ordinary
, farm road, for example, usually re
/ quires no survey other than lining /
by the eye between the controlling
q points. Some unimportant public road
: may require very little more than farr
g roads in the way of survey, but
: any considerable amount of grading 0
! other work is to be done, either at tn
f time the road is located or later tn
survey should include all instrumen
work necessary to insure that the worl
will be done economically.
, The purposes of a survey are ~ tt
determine accurately the topography
or lay of the land so that the loca
ton may follow the route which pre-.
sents the fewest obstacles, (2) to fiji
the grade line to the ground surface so
as to keep down the amount of grading
necessary, (3) to balance cuts and fills
so that whatever grading is done will
be to the best possible advantage, az
to line up the road and provide stakes
for controlling the work, 90 to obtain
data from which proper plans may be-
prepared and an estimate of cost made,
(6) to provide record that will pre-
vent subsequent contentious among
landowners regarding the original To-
cation of the road. While the impor-
lance of all these purposes is apparent,
frequently it is not realized that they
cannot be accomplished except by
means of careful survey, and that
such surveys can be made only by ex-
perienced men who have been trained
especially for such work Farmers
and business men generally are in
clined to underestimate the amount OF
skill required to make a road survey
properly and their influence has been
responsible in the past for much bung-
ling and for uneconomical road work
for which they have had to pay in
heavy taxes.
The accompanying fgur 'llustra tes
an error which is made times by
| inexperienced persons in grading
road without first having surveyed and
planned the work. In this figure, which
is an actual profile of an existing road,
the shaded line shows the original
ground surface, the heavy full line
shows the grade to which the road was
actually constructed, and the dotted
line shows a grade line which, if it had
been followed, not only would have re-
quired no additional work, but would
have reduced the steep grade material
ly and thereby improved the road con-
siderably.
In fitting the grade line to the ground
surface and balancing cuts ard fills it
should be borne in mind that earth,
after being thoroughly compacted, will
occupy less space in an embanEment or
fill than in its original positioa. The
customary allowances for sh-inkage
and waste in road work are:
Par cent
| For heavy cuts and fills..............i0 to IS
For average grading .........s.......I5 to 20
i For light grading ....................50 to 30
For very light grading and consid-
eraple 500 ...............-.....,....3O to 10
Solid rock will expand from one
third to one-half of its original volume
when taken from a cut or excavation
and placed in an embankment But