92 Ill. Adm. Code 550.70
Commercial Driveway Requirements (Illustrations E and F)
Section 550
Section 550.70 Commercial
Driveway Requirements (Illustrations E and F)
a) Width of Drive. All commercial driveways shall be limited to
a maximum width of 35 feet measured at right angles to the center line of the
drive, exclusive of flares. The width may be increased by permissible radii to
allow for smooth ingress and egress at the highway connection. The maximum
permissible width for rural locations shall be 60 feet measured along a line 6
feet from and parallel to the roadway edge. For urban locations, the maximum
width shall be 85 feet measured at the face of the curb.
b) Radius of Flare. The flare used to connect the driveway to
the roadway shall normally fall entirely within the right-of-way. It may be
permitted to go outside the right-of-way if raised curbing extends into the
private property. In rural locations, the radii shall be between 10 and 40
feet, while in urban cases they shall be between 10 and 25 feet. In special
cases, after consideration of the right-of-way width, proposed volumes, types
of vehicles, speeds on the roadway, and parking regulations, radii outside
these ranges may be permitted to allow for the efficient use of the driveway.
The geometrics necessary for smooth operation of the driveway may require the
use of modified radii flares or three-center curves with or without island.
c) Angular Placement. The center line of a single driveway that
services a commercial property should generally be at a right angle to the
roadway or parallel to the property line. The angle of the center line with
the roadway may be reduced to 60 degrees for two-way driveways or 45 degrees
for multiple entrances where the driveways will be used for one-way traffic.
Angled driveways may be allowed for high-speed roadways and/or large volume
movements.
d) Location.
1) Sufficient distance must be maintained between the property
line and the edge of the driveway to allow for the construction of an adequate
island between drives should the adjacent property owner desire to build an
entrance. In rural locations, this distance shall be measured along a line 6
feet from and parallel to the roadway edge and should be a minimum of 5 feet.
In urban situations, a curb length of not less than 3 feet shall be left
undisturbed adjacent to each property line.
2) All commercial driveways shall be located to provide a
specified minimum distance from the intersecting public roads. This distance
shall be measured along a line parallel to but not greater than 5 feet from the
pavement edge. For rural locations, the minimum distance between the beginning
of the flare and the edge of the intersecting road shall be 50 feet. At urban
locations, the beginning of the flare must be at least 5 feet from the
extension of the near right-of-way line of the intersecting road. In no case
shall the distance between the point at which the edge of the driveway
intersects the pavement edge and the line of the through traffic lane extended
be greater than 5 feet. Where a separate right-turn lane is provided, no part
of the lane taper shall encroach on the highway flare.
e) Islands. Where a commercial establishment is serviced by more
than one driveway, an island separator shall be provided and maintained between
drives. The back edge of this island measured along the right-of-way line
should have a minimum length of 10 feet for rural and 6 feet for urban
locations. The island width 6 feet from the edge of the highway must also meet
these minimums. Where the island is less than 25 feet long or less than 10 feet
in width, its shape shall be defined by the use of concrete curb, masonry, or
other devices to restrict the path of vehicles using the driveways.