92 Ill. Adm. Code 533.60
Vehicles
Section 533
Section 533.60 Vehicles
a) Vehicles are restricted to surfaced areas only and operators
shall obey all traffic signs and markings.
b) Rest areas shall not be used as a relay station or transfer
point for trailers or cargo in transit. No cargo, trailer, or mobile home
shall be uncoupled from its power unit within the rest area, except in the case
of mechanical breakdown or other emergency.
c) Vehicles shall occupy no more than one marked parking space.
d) Rest areas shall not be used to change oil or to perform any
other automotive service. Minor repairs will be allowed.