IL
Illinois oversize permit rules
What Illinois charges for a single-trip OS/OW permit, the limits that trigger one, and the escort thresholds — read from the state’s own publication. This rule has been in effect since 2024-08-07; we last read the source on 2026-07-10.
Oversize permit
$12–$125
The load has to fit inside a tier on every dimension at once — width and height and length. Exceed any one of them and it falls to the next tier up.
Overweight permit
From $10
Scales with weight and axle count — there is no single figure.
A load that is both oversize and overweight pays this fee only, not both.
+ $20 Permigo service fee per permit, state fees at cost.
Legal limits
Exceed any one of these in Illinois and you need a permit for this state.
| Limit | Interstate |
|---|---|
| Width | 8'6" |
| Height | 13'6" |
| Length | 80'0" |
| Gross weight | 80,000 lbs |
| Single axle | 20,000 lbs |
| Tandem axle | 34,000 lbs |
| Trailer length | 53'0" |
What the permit costs
Illinois prices a single-trip permit as by dimensional envelope. The load has to fit inside a tier on every dimension at once — width and height and length. Exceed any one of them and it falls to the next tier up.
| Band | State fee |
|---|---|
| Within 10'0" wide × 14'6" high × 70'0" long (by distance) | $12–$21 |
| Within 12'0" wide × 14'6" high × 85'0" long (by distance) | $15–$30 |
| Within 14'0" wide × 15'0" high × 100'0" long (by distance) | $25–$40 |
| Within 18'0" wide × 16'0" high × 120'0" long (by distance) | $30–$60 |
| Anything larger (by distance) | $50–$125 |
Escort requirements
Thresholds by road class. Where two classes differ, the road you are actually on governs.
Multilane divided
| Width | Requirement |
|---|---|
| Over 8'6" | 1 rear escort (night only)Oversize loads up to 12'0" wide / 13'6" high / 200' long may move 24/7, but darkness hours require one additional civilian escort (OPER 993 Authorized Times: 'authorized to move 24 hours a day, 7 days a week with one additional civilian escort when traveling during the hours of darkness'). This escort bills only when night travel is planned. |
| Over 12'0" | Not permittedOver 12'0" wide: daylight movement only (½ hr before sunrise to ½ hr after sunset). 24/7 movement is authorized only up to 12'0" wide / 13'6" high / 200' long (OPER 993 Authorized Times).Cook County expressway prohibition: loads over 12'0" wide, 13'6" high, or 120,000 lb are prohibited on Cook County expressways except I-80 (I-57 east to Indiana), I-55 south of exit 277, I-57 south of US 6 (159th St.), and I-290 north of Toll I-294 (OPER 993). City of Chicago streets need a separate city permit (312-744-4699); Cook County highways 312-603-1670. |
| Over 14'6" | 1 rear escort · superloadOver 14'6" wide: ONE civilian escort (OPER 993 Provision B: 'One civilian escort is required for all moves that 1) exceed 14' 6" wide…'). Escort position flips by road type (IDOT policy book 554.1240(d): "When only one escort vehicle is required and when operating on a two-lane highway, the escort vehicle shall travel ahead of the load... When operating on a multilane divided highway, the escort vehicle shall trail the load"; ~300 ft spacing). Width >14'6" is also a superload trigger (554.1320(a): 'the movement of vehicles or objects exceeding 14 feet 6 inches in width requires a superload permit'); on an overweight permit an additional Table 1 fee applies (Table 2 footnote).Width 14'6"–16'0": travel restricted to 9:00am–3:00pm Mon–Fri in Cook, DuPage, Lake, Kane, Madison, McHenry, Monroe, St. Clair and Will counties (OPER 993 Provision 9(a)). |
| Over 16'0" | 1 front escort + 2 rear escortsOver 16'0" wide: THREE civilian escorts (OPER 993 Provision B). IDOT fixes only the lead/trail logic, not the 3-vehicle splitOver 16'0" wide additionally requires an IDOT district investigation ($40 per district; reusable for identical moves within 21 days — IDOT policy book 554.1320).Over 16'0" wide: movement 9:00am–3:00pm CST Mon–Fri only; no Saturday or Sunday movement (OPER 993 Authorized Times). |
| Over 18'0" | 1 police escortOver 18'0" wide: Illinois State Police escort required (OPER 993 Provision B) — set up ≥24 working hours ahead with ISP Central Office 217-782-6527 ($80 per ISP district, $160 for the Chicago District — 554.911). Moves >18' wide are generally authorized only on Interstates and other multilane controlled-access highways (554.505(b)) and must maintain minimum posted speeds. |
| Height | Requirement |
|---|---|
| Over 13'6" | Not permittedOver 13'6" high: verify overhead clearances along the route; daylight-tier travel windows apply above the 24/7 tier (OPER 993 Authorized Times). Chicago-area controlled-access routes cap permit heights at 13'6" (554.508(b)); Cook County expressway prohibition applies over 13'6" (OPER 993). |
| Over 14'6" | 1 front escort · height poleOver 14'6" high: ONE civilian escort that must LEAD the load carrying a height pole on every road type (554.408(k)/554.1240(l): 'A pole for measuring vertical clearances shall be mounted on escort vehicles leading loads in excess of 14 feet 6 inches in height') — the pole rides the required escort; it is not an additional vehicle. Pole set 3 inches above the permitted load height (OPER 993 Provision 4). |
| Over 15'0" | superload permitOver 15'0" high: exceeds the practical maximum height ('The practical maximum height is 15 feet', 554.508(a)) — superload review; an additional Table 1 fee applies on an overweight permit (Table 2 footnote) and the movement window narrows (OPER 993 Authorized Times). |
| 16'0" and over | route survey16'0" or higher: THE APPLICANT performs a route survey listing all overhead obstructions; the surveyed route must clear all structures by three inches (554.508(e) — verbatim-verified). At 17'0" or higher the applicant must also contact all overhead-utility companies and a District route survey applies (554.508(f)); >17' high drops to the 9:00am–3:00pm Mon–Fri window. NOTE: the pending Part 554 rewrite keeps only the 17' tier — watch JCAR. |
| Over 18'0" | 1 front escort + 2 rear escorts · 1 police escortOver 18'0" high: THREE civilian escorts + Illinois State Police (OPER 993 Provision B — operative; the 2012 codified rule 554.407(b)(1) still prints TWO civilians — IDOT enforces OPER 993). ISP waivable when a district investigation shows no overhead obstructions (554.407(d)(2)(C)). |
| Length | Requirement |
|---|---|
| Over 110'0" | 1 rear escortOver 110' long: ONE civilian escort (OPER 993 Provision B: '…or 3) exceed 110' long.'). Escort position flips by road type (IDOT policy book 554.1240(d): "When only one escort vehicle is required and when operating on a two-lane highway, the escort vehicle shall travel ahead of the load... When operating on a multilane divided highway, the escort vehicle shall trail the load"; ~300 ft spacing). |
| Over 145'0" | 1 front escort + 2 rear escorts · superloadOver 145' long: THREE civilian escorts (OPER 993 Provision B) and superload treatment — 145' is the practical maximum length (554.507(b)); an additional Table 1 fee applies on an overweight permit (Table 2 footnote). Split |
| Over 200'0" | 1 police escortOver 200' long: Illinois State Police escort (OPER 993 Provision B). Movement ½ hr before sunrise to ½ hr after sunset Mon–Fri; no Saturday or Sunday movement (OPER 993 Authorized Times). |
| Front overhang | Requirement |
|---|---|
| Over 3'0" | No escort required |
| Weight | Requirement |
|---|---|
| Over 120,000 lbs | route survey · superloadGVW over 120,000 lb exceeds the 6+-axle practical maximum — superload. Per-configuration practical maxima are lower (5-axle 100,000 / 4-axle 76,000 / 3-axle 68,000 / 2-axle 48,000 — 554.604): exceeding the applicable envelope is a superload even under 120,000 lb, and rigs missing the minimum axle spacings (steer-to-drive ≥8'1", ≥18'6" to the first trailer axle, spacing sum ≥43'6") are automatically processed as superloads (OPER 993/554.1415). Fee via the IDOT ITAP Superload Fee Calculator; bridge/pavement analyses billed at $40/hr; superload windows are typically 9:00am–3:00pm; Cook County expressway prohibition applies over 120,000 lb. ISP is NOT automatic on weight — discretionary after bridge analysis or district investigation (OPER 993 Provision B). |
2-lane (undivided)
| Width | Requirement |
|---|---|
| Over 8'6" | 1 front escort (night only)Oversize loads up to 12'0" wide / 13'6" high / 200' long may move 24/7, but darkness hours require one additional civilian escort (OPER 993 Authorized Times: 'authorized to move 24 hours a day, 7 days a week with one additional civilian escort when traveling during the hours of darkness'). This escort bills only when night travel is planned. |
| Over 12'0" | Not permittedOver 12'0" wide: daylight movement only (½ hr before sunrise to ½ hr after sunset). 24/7 movement is authorized only up to 12'0" wide / 13'6" high / 200' long (OPER 993 Authorized Times).Cook County expressway prohibition: loads over 12'0" wide, 13'6" high, or 120,000 lb are prohibited on Cook County expressways except I-80 (I-57 east to Indiana), I-55 south of exit 277, I-57 south of US 6 (159th St.), and I-290 north of Toll I-294 (OPER 993). City of Chicago streets need a separate city permit (312-744-4699); Cook County highways 312-603-1670. |
| Over 14'6" | 1 front escort · superloadOver 14'6" wide: ONE civilian escort (OPER 993 Provision B: 'One civilian escort is required for all moves that 1) exceed 14' 6" wide…'). Escort position flips by road type (IDOT policy book 554.1240(d): "When only one escort vehicle is required and when operating on a two-lane highway, the escort vehicle shall travel ahead of the load... When operating on a multilane divided highway, the escort vehicle shall trail the load"; ~300 ft spacing). Width >14'6" is also a superload trigger (554.1320(a): 'the movement of vehicles or objects exceeding 14 feet 6 inches in width requires a superload permit'); on an overweight permit an additional Table 1 fee applies (Table 2 footnote).Width 14'6"–16'0": travel restricted to 9:00am–3:00pm Mon–Fri in Cook, DuPage, Lake, Kane, Madison, McHenry, Monroe, St. Clair and Will counties (OPER 993 Provision 9(a)). |
| Over 16'0" | 2 front escorts + 1 rear escortOver 16'0" wide: THREE civilian escorts (OPER 993 Provision B). IDOT fixes only the lead/trail logic, not the 3-vehicle splitOver 16'0" wide additionally requires an IDOT district investigation ($40 per district; reusable for identical moves within 21 days — IDOT policy book 554.1320).Over 16'0" wide: movement 9:00am–3:00pm CST Mon–Fri only; no Saturday or Sunday movement (OPER 993 Authorized Times). |
| Over 18'0" | 1 police escortOver 18'0" wide: Illinois State Police escort required (OPER 993 Provision B) — set up ≥24 working hours ahead with ISP Central Office 217-782-6527 ($80 per ISP district, $160 for the Chicago District — 554.911). Moves >18' wide are generally authorized only on Interstates and other multilane controlled-access highways (554.505(b)) and must maintain minimum posted speeds. |
| Height | Requirement |
|---|---|
| Over 13'6" | Not permittedOver 13'6" high: verify overhead clearances along the route; daylight-tier travel windows apply above the 24/7 tier (OPER 993 Authorized Times). Chicago-area controlled-access routes cap permit heights at 13'6" (554.508(b)); Cook County expressway prohibition applies over 13'6" (OPER 993). |
| Over 14'6" | 1 front escort · height poleOver 14'6" high: ONE civilian escort that must LEAD the load carrying a height pole on every road type (554.408(k)/554.1240(l): 'A pole for measuring vertical clearances shall be mounted on escort vehicles leading loads in excess of 14 feet 6 inches in height') — the pole rides the required escort; it is not an additional vehicle. Pole set 3 inches above the permitted load height (OPER 993 Provision 4). |
| Over 15'0" | superload permitOver 15'0" high: exceeds the practical maximum height ('The practical maximum height is 15 feet', 554.508(a)) — superload review; an additional Table 1 fee applies on an overweight permit (Table 2 footnote) and the movement window narrows (OPER 993 Authorized Times). |
| 16'0" and over | route survey16'0" or higher: THE APPLICANT performs a route survey listing all overhead obstructions; the surveyed route must clear all structures by three inches (554.508(e) — verbatim-verified). At 17'0" or higher the applicant must also contact all overhead-utility companies and a District route survey applies (554.508(f)); >17' high drops to the 9:00am–3:00pm Mon–Fri window. NOTE: the pending Part 554 rewrite keeps only the 17' tier — watch JCAR. |
| Over 18'0" | 2 front escorts + 1 rear escort · 1 police escortOver 18'0" high: THREE civilian escorts + Illinois State Police (OPER 993 Provision B — operative; the 2012 codified rule 554.407(b)(1) still prints TWO civilians — IDOT enforces OPER 993). ISP waivable when a district investigation shows no overhead obstructions (554.407(d)(2)(C)). |
| Length | Requirement |
|---|---|
| Over 110'0" | 1 front escortOver 110' long: ONE civilian escort (OPER 993 Provision B: '…or 3) exceed 110' long.'). Escort position flips by road type (IDOT policy book 554.1240(d): "When only one escort vehicle is required and when operating on a two-lane highway, the escort vehicle shall travel ahead of the load... When operating on a multilane divided highway, the escort vehicle shall trail the load"; ~300 ft spacing). |
| Over 145'0" | 2 front escorts + 1 rear escort · superloadOver 145' long: THREE civilian escorts (OPER 993 Provision B) and superload treatment — 145' is the practical maximum length (554.507(b)); an additional Table 1 fee applies on an overweight permit (Table 2 footnote). Split |
| Over 200'0" | 1 police escortOver 200' long: Illinois State Police escort (OPER 993 Provision B). Movement ½ hr before sunrise to ½ hr after sunset Mon–Fri; no Saturday or Sunday movement (OPER 993 Authorized Times). |
| Front overhang | Requirement |
|---|---|
| Over 3'0" | No escort required |
| Weight | Requirement |
|---|---|
| Over 120,000 lbs | route survey · superloadGVW over 120,000 lb exceeds the 6+-axle practical maximum — superload. Per-configuration practical maxima are lower (5-axle 100,000 / 4-axle 76,000 / 3-axle 68,000 / 2-axle 48,000 — 554.604): exceeding the applicable envelope is a superload even under 120,000 lb, and rigs missing the minimum axle spacings (steer-to-drive ≥8'1", ≥18'6" to the first trailer axle, spacing sum ≥43'6") are automatically processed as superloads (OPER 993/554.1415). Fee via the IDOT ITAP Superload Fee Calculator; bridge/pavement analyses billed at $40/hr; superload windows are typically 9:00am–3:00pm; Cook County expressway prohibition applies over 120,000 lb. ISP is NOT automatic on weight — discretionary after bridge analysis or district investigation (OPER 993 Provision B). |
Movement restrictions
| Restriction | In Illinois |
|---|---|
| Night travel | Daylight hours only |
| Weekends | No blanket restriction |
| Holidays | Restricted |
Authorized times of movement (OPER 993, verified 2026-07-10)
| Load | Window |
|---|---|
| OW only, legal dims | 24 hours, 7 days |
| ≤12′W · ≤13′6″H · ≤200′L | 24/7 — +1 civilian escort during darkness |
| ≤14′6″W · ≤15′H · ≤200′L | ½ hr before sunrise → ½ hr after sunset, 7 days |
| ≤16′W · ≤17′H | same window Mon–Fri + Saturday until noon; if >14′6″W: 9a–3p M–F in the 9 Chicago/Metro-East counties |
| >16′W or >17′H | 9:00am–3:00pm Mon–Fri only, statewide; no weekend |
| >200′L | daylight Mon–Fri; no weekend |
| 6 holidays | blackout: noon before → ½ hr before sunrise after (OS loads; OW-only w/ legal dims exempt) |
Where these permits come from
If you file yourself, this is the office you are dealing with. Check the linked page — some states issue OS/OW permits through their highway patrol or revenue department rather than the DOT.
| Illinois permit office | |
|---|---|
| Permit office | (217) 785-1477 |
| [email protected] | |
| Permit portal | webapps.dot.illinois.gov/ITAP — orders 24/7, most permits auto-issue; superloads issued 7:30a–4:30p M–F |
| Information | Official page |
IDOT Table 1 Rev. 1/16/2024 + Table 2 + OPER 993 Rev. 08/07/24 + OPER 753 Rev. 01/05/23 + 625 ILCS 5/ch.15 + 92 IAC 5… · idot.illinois.gov · in effect since 2024-08-07 · source read 2026-07-10. Fees and rules change; the linked document is always the authority.