92 Ill. Adm. Code 550.80
Industrial-Commercial-Recreational High-Volume Traffic Generator Driveway Requirements (Illustration G)
Section 550
Section 550.80
Industrial-Commercial-Recreational High-Volume Traffic Generator Driveway
Requirements (Illustration G)
a) This category is for industrial or commercial complexes that
generate high-volume traffic, such as shopping centers, office buildings,
apartment or residential complexes, and also includes recreational facilities,
such as racetracks, athletic parks, and drive-in theaters.
b) It is difficult to establish standards for these types of
driveways because of the uniqueness of each one and the critical effect each
may have on the operation of the highway onto which the driveway is to be
constructed. They should meet the standards for public road intersections with
corresponding traffic, although each such entrance will need to be individually
designed.
c) It is recommended that a preliminary meeting between the
developer and the Department be held to discuss entrance location prior to the
final arrangement of buildings, internal driveways, and parking facilities
within the entire development.
d) The permit request must be accompanied with the final site
layout and other information necessary to review the proposed entrances.
Traffic and drainage studies may also be needed.
e) The following general requirements will pertain to these types
of driveways.
1) Width of Drive. A driveway for these types of developments
may have a maximum width of 35 feet when undivided or may consist of two
24-foot drives, one for entering and one for exiting traffic, divided by a
median. The entrance to the development shall be designed to avoid backing up
traffic on the highway so that traffic waiting to enter into the facility
blocks through traffic. The number of lanes exiting from the development and
turning in one direction shall not exceed the number of available traffic lanes
on the highway in that direction. For example, if the exit is on a two-lane
two-way pavement, no more than one lane will be allowed to exit at the same
time in each direction.
2) 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. The radii will generally be between 30 and 50 feet, except
that three-center curves, with or without island, may be required. Vehicle
turning paths should be used to design the flares to prevent vehicles using the
driveway from encroaching outside the right lane of the highway.
3) Angular Placement. The center line of a two-way driveway
shall either be at a right angle to the roadway or parallel to the property
line. The angle of the center line of the driveway is 60 degrees for a two-way
driveway or 45 degrees for multiple entrances where the driveways will be used
for one-way traffic.
4) Location.
A) A minimum distance of 10 feet shall be maintained between a
property line and any part of the driveway flare. The distance between the
beginning of the driveway flare and the near edge of an adjacent roadway
intersecting the State highway shall be 100 feet. Where volume projections
indicate a need, sufficient distance from adjacent roadways or property lines
should be allowed for the construction of a right or left-turn lane.
B) If multiple drives are provided for these facilities,
sufficient distance must be allowed between entrances for the construction of
turning lanes. This will also result in separating the points of conflict
created by such entrances and will encourage internal circulation. A minimum
distance of 440 feet between the center lines of adjacent entrances will be
required for these purposes.
5) Medians. Where a divided entrance separating entering and
exiting traffic is utilized, the median shall be between 4 and 18 feet wide and
extend into the property as far as necessary to promote smooth traffic
patterns. The median shall begin at the edge of the normal shoulder in an
uncurbed section or 4 to 10 feet from the face of the curb in a curbed section.