Q2 Z2,(Q2) Z2(Q2) - Institute for Water Resources - U.S. Army

similar and therefore
OC _ OE _ CE
OD - OF DF
DIAGRAM 9
Then, when OD = 20C, OF = 20E, and DF = 2CE, so that the costs of the two
routes must be equal at D. The frontier is linear as it was constructed, the
magnitude of 0 depending on the values of C r C . and C w . Nothing would be
. changed to the triangular shape of the bohndary if additional costs proportional
to the .distance were added to the model.
It remains then, to'introduce costs which are not proportional to
the distance and which do not cancel each other as being equal for the two
routes. Let us introduce the cost of transshipment and the costs of loading-
unloading. As far as the choice of the less expensive truck-barge route is
concerned, nothing is changed: the charges or costs L w-and Lt are constant and
are applied for all possible indirect routes. Therefore, the angle y t is the
same as before. However, the frontier does not necessarily reach the origin.
In the likely case where C w < Cr , a minimum distance of. transportation on the
waterway is required in order to make up for the additional cost involved by
X
71.