When a 44, a pricing policy that is based on the fourth power
leads to values of PRICE4 that are too high for most axles (the
relatively light ones). Using the fact that the total paid by all
vehicles is constant (with respect to p), this means that the fewer
remaining (relatively heavy) axles are currently highly ‘‘sub-
sidized’’ by the lighter ones. Using similar reasoning, when a o4,
the values of PRICE4 are too low for most axles (the relatively light
ones), whereas the fewer heavier axles are currently overpaying.
Therefore, it is important that a highway agency use the