Illinois/Major roads Discussion View history

Based off: Functional Classification Maps from IDOT Home page

Also the Getting Around Illinoishas the functional class map that may be easier to pan around on.

US Route and State Route Naming

• In July,2013, all US Hwy XXX have been changed to US-XXX.

• State Rte XXX is being changed to SR-XXX format.
• CR-XXX will be used where applicable. Most have a Primary Street name, so this would only apply to an Alternate Field entry.

FC cross reference

Refer to this chart to determine the road type of a given road based on the functional class.

To use this chart, first determine the functional class of a road, and whether it is a signed, numbered highway in a particular highway system.

Where the column for the road's highway system and the row for the road's functional class meet, you will find the proper road type for that particular road.

A number of examples are given below the chart.

		Highway Systems
		Interstate	Interstate Business Loop/Spur	US Hwy (incl. some [routes])	US Hwy BUS, SPUR, LOOP	State Hwy (incl. some special routes)	State Hwy BUS, SPUR, LOOP	County Route	Locally-maintained
	example	I-90 E	I-55 Business	US-12	US-460 Business	SR-22	SR-400 Loop	CR-15	Robertson St
F u n c t i o n a l C l a s s	Interstate	Fw	n/a	n/a	n/a	n/a	n/a	n/a	n/a
	Freeway	n/a	Fw	Fw	Fw	Fw	Fw	Fw	Fw
	Expressway	n/a	Major	Major	Major	Major	Major	Major	Major
	Other Principal Arterial	n/a	Major	Major	Major	Major	Major	Major	Major
	Minor Arterial	n/a	Major	Major	Minor	Minor	Minor	Minor	Minor
	Major Collector	n/a	Major	Major	Minor	Minor	PS	PS	PS
	Minor Collector	n/a	Major	Major	Minor	Minor	PS	PS	PS
	Local/not mapped	n/a	Major	Major	Minor	Minor	PS	PS	Street

^a When a state highway "SPUR" route is used to connect a state highway with another state highway, a US highway, or an Interstate (i.e., when it is used as a connector/CONN route), use the first state highway column.

For example,

• An Interstate Business Loop classified as a Minor Arterial is a  Major Highway .
• A US Highway classified as a Minor Arterial is a  Major Highway .
• A US Highway Spur route classified as a Minor Arterial is a  Minor Highway .
• A State Highway classified as an Other Freeway is a  Freeway .
• A State Highway classified as a Collector is a  Minor Highway .
• A County Route classified as a Minor Arterial is a  Minor Highway .
• A County Route classified as a Collector is a  Primary Street 
• A locally-maintained road classified as an Other Principal Arterial is a  Major Highway .
• A locally-maintained road classified as a Collector is a  Primary Street .

Fw	Freeway
Major	Major Highway
Minor	Minor Highway
PS	Primary Street
Street	Street

Freeways

These are interstates, highways, freeways, toll roads, and expressways that are multi-lane, divided roads with no stops (no traffic lights, exit and entrance from/to the road is through ramps). All roads labeled Interstate on the IDOT Functional Class map. Some IDOT classified Freewway or Expressway may fall in this catagory as well.

Road	Dir	Northern/ Western End	Southern/ Eastern End	Toll Road?	Notes
I-24	W/E	I-57 South of Marion	KY Border Ohio River	N
I-39	N/S	WI Border	I-55 Normal	N*	Tollway while joined with I-90 from Rockford to WI border.
I-55	N/S	US 41 (Lake Shore Dr / Chicago)	MO Border East St. Louis	N	Known as Stevenson Expressway within Cook County.
I-57	N/S	I-94 Chicago	MO Border Mississippi River	N
I-64	W/E	MO Border East St. Louis	IN Border Wabash River	N
I-70	W/E	MO Border Mississippi River	IN Border	N
I-72	W/E	MO Border Mississippi River	I-57 Champaign	N
I-74	W/E	IA Border Mississippi River	IN Border	N
I-80	W/E	IA Border	IN Border	N*	Tollway portion between I-94 at Thornton and I-294 near Hazel Crest. Tollway portion known as (part of) the Tri-State Tollway.
I-88	W/E	IA Border	I-290/I-294	Y*	Tollway from mile marker 44 (US-30) to eastern terminus. West of US-30 is a freeway. Toll road portion is known as the Ronald Regan Memorial Tollway.
I-90	W/E	WI Border	IN Border	Y*	Tollway from US-51 (WI Border) to east of O'Hare airport (near IL-171 / Cumberland Ave) and from south of Chicago to the IN border. Toll portion from WI border to Chicago area is known as the Jane Addams Memorial Tollway. Freeway portion is known as the Kennedy Expressway north of downtown Chicago (I-290 junction) and Dan Ryan Expressway south of downtown Chicago (I-290 junction). Southeast tollway portion is known as the Chicago Skyway to the IN border.
I-94	W/E*	WI Border	IN Border	N*	Direction of travel in IL is mostly N/S but designation is W/E. Tollway from Deerfield (I-294 junction) to US-41. Tollway portion known as (part of) the Tri-State Tollway. Freeway portion known as the Edens Expressway until it joins I-90.
I-155	N/S	I-74 Morton	I-55 Northwest of Lincoln	N
I-172	N/S	US-24 North of Quincy	I-72 South of Quincy	N	Formerly called the Central Illinois Expressway
I-180	N/S	I-80 Princeton	IL-26 Hennepin	N
I-190	W/E	O'Hare International Airport Chicago	I-90 Chicago	N
I-255	N/S	MO Border Mississippi River	I-270/IL-255 East of Alton	N
I-270	W/E	MO Border Mississippi River	I-70 Northwest of Troy	N
I-280	W/E	IA Border Mississippi River	I-74/I-80 Colona	N
I-290	W/E	I-90 East of Schaumburg	I-90/94 Downtown Chicago	N	Known as the Eisenhower Expressway.
I-294	N/S	I-94 near Lake-Cook County Line	I-80/IL-394 West of Lansing	Y	Known as (part of) the Tri-State Tollway.
I-355	N/S	I-290 Itasca	I-80 New Lenox	Y	Known as the Veterans Memorial Tollway.
I-474	W/E	I-74/IL-6 Peoria	I-74 East Peoria	N

Major Highway

Principal arterials are the primary routes for traveling throughout the country, from one city to another, over long distances. Many principal arterials are freeways or expressways, but many others are not.

As a nationwide system, the United States Numbered Highways, or U.S. Highways, system provides a direct links between regions not served by the Interstate Highway System, and as alternatives to Interstate travel in the case of heavy traffic or incident.

In Illinois, the Functional Classification is Other Principal Arterial.

Road	Dir	Northern/ Western End	Southern/ Eastern End	Notes
US-12	E/W	Wisconsin	Indiana

Minor Highways

Minor arterials (or other arterials) are secondary routes for traveling between cities over moderately long distances. Minor or other arterials are classified in Waze as Minor Highways.

In Illinois, these are numbered the state highway system. Roads in these systems are designated and selected by the Illinois State Department of Transportation as part of statewide networks of important travel links between cities and communities of those states. These roads, while of lesser national importance, are nevertheless essential for travel within the state. In Illinois these are designated as Minor Arterial.

Road	Dir	Northern/ Western End	Southern/ Eastern End	Notes
IL 83	N/S	Devon Ave (Elk Grove Village)	31st St (Oak Brook)

Primary Street

Collectors are roads used with medium-low traffic densities which are used to bring traffic from local streets to arterials and vice versa. Collectors are classified in Waze as Primary Streets. Some states designate county routes which are important for travel within a county. These routes serve important functions in a short-distance capacity. On the Illinois Functional Class map, these will be Major Collectors and Minor Collectors.

Road	Dir	Northern/ Western End	Southern/ Eastern End	Notes
Boughton Rd	W/E	Naperville-Plainfield Rd (Bolingbrook)	Woodward Ave (Woodridge)	Continues east as 87th St

To Be Categorized

These roads still have to be put in their proper places above.

Road	Dir	Northern/ Western End	Southern/ Eastern End	Notes
US 6	W/E	IA-IN borders (Moline - Lansing)		Grand Army of the Republic Highway