Section 105IAC10-3-2. Calculation of ESAL values

   (a) The ESAL value for each axle group shall be calculated as follows:

(1) The ESAL value for each axle shall be calculated as the actual axle weight, divided by the axle group divisor (as defined in subdivision (4), below), all raised to the fourth power ((weight/divisor)^4). (See the sample equation shown in Figure 1.)

(2) The numerator for each axle group is the sum of the gross axle weights of all individual axles within that axle group, or the combined GAW.

(3) The divisor for each axle group depends on the number of axles in the group.

(4) Divisors shall be as follows:

(A) If the axle group consists of a single axle, the divisor is eighteen thousand (18,000) pounds.

(B) If the axle group consists of a tandem axle (that is, two (2) individual axles), the divisor is thirty-three thousand two hundred (33,200) pounds.

(C) If the axle group consists of a tridem axle (that is, three (3) individual axles), the divisor is forty-six thousand (46,000) pounds.

(D) If the axle group consists of a quad axle (that is, four (4) individual axles), the divisor is fifty-seven thousand (57,000) pounds.

(E) If the axle group consists of a quintuple axle (that is, five (5) individual axles), the divisor is sixty-five thousand (65,000) pounds.

(5) The resultant fraction quantity is raised to the fourth power.

Figure 1. Examples of calculations for a single axle and a tandem axle.

Where:

W

=

Gross axle weight (GAW).

  (b) ESAL value for the sum of all axles of the vehicle shall be calculated as follows: (ESAL=Axle1 ESAL+Axle2 ESAL+Axle3 ESAL+…AxleN ESAL). (See the sample calculation shown in Figure 2.) The total vehicle ESAL value is the sum of all axle group ESAL values.

Figure 2. Example of calculation of total vehicle ESAL value.

  (c) This section shall apply to all calculations of ESAL values throughout this article. (Indiana Department of Transportation; 105 IAC 10-3-2; emergency rule filed Dec 26, 2013, 1:48 p.m.: 20140108-IR-105130568ERA, eff Jan 1, 2014)