Procedure with Unequal Zones or Irregular Lots.
—Where the zones are not equal in area or the property lines do not intersect the roadway at right angles or the lots are irregular in shape, the method of procedure is not quite so simple, although the principle is the same. While it is customary to make the zones of uniform width this is not absolutely necessary. Likewise the ratio of weights vary with different states and cities. One city uses 331⁄3, 20, 162⁄3, 10, 10, 10 for the weights in its six zones; another uses 331⁄3, 25, 162⁄3, 15 and 10. Neither of these, as shown in the tables on [pages 315] and [316] varies materially from the theoretical ratio.
Using the latter of these ratios a small district has been worked out as shown in the figure and table on [page 320]. Incidentally this also shows a good method of recording lot assessments during the process of computations. The work is readily checked. The sum of the lot areas must equal the sum of the zone areas and that of the whole district. The sums of the weighted areas for the same divisions must balance. The sums of front-feet likewise. Also cross and vertical summations may be made to check.
