Ill. Admin. Code tit. 92, § 1536.20
a) The hearing examiner shall assign the crossing proposed for closure to one of the following categories:
b) The categories listed in subsection (a) of this Section shall be differentiated by:
2) the crossing's Train Volume and Speed Index (TVSI), which is calculated by taking the average number of freight and passenger train movements per day which use the crossing and multiplying each by their maximum timetable train speed. This calculation is represented by the following equation:
TVSI = (Tf x Sf) + (Tp x Sp)
Where:
TVSI = Train Volume and Speed Index
Tf = Average number of freight trains/day
Tp = Average number of passenger trains/day
Sf = Maximum timetable speed for freight trains
Sp = Maximum timetable speed for passenger trains
c) The ADT and TVSI thresholds for each category are:
| Category | Characteristics | Closure Criteria |
| 1: | Incorporated/Signalized* | ADT ≤125 and TVSI ≥ 240 |
| 2: | Incorporated/Unsignalized | ADT ≤175 and TVSI ≥ 240 |
| 3: | Unincorporated/Signalized* | ADT ≤75 and TVSI ≥ 300 |
| 4: | Unincorporated/Unsignalized | ADT ≤100 and TVSI ≥ 300 |
* Where signal equipment or last circuitry update is 10 years old or older.
d) The Commission shall determine if the crossing meets the following criteria:
g) The alternate roadway shall be considered adequate if:
4) rerouting of the crossing's vehicular traffic over the alternate roadway will not have a significant adverse effect on public safety. Factors to be considered in making this determination include:
i) The alternate public crossing will not be considered adequate if the amount of adverse distance, as measured along the centerline of the routes which comprise the alternate roadway, which the closure will cause: