How § 343.307(1) cross-counts Illinois DUI
Wisconsin Statute § 343.307(1) establishes the master list of "counted priors" for Wisconsin OWI charging. The list includes:
- Wisconsin OWI convictions (including 1st-offense civil forfeitures)
- Wisconsin refusal revocations under § 343.305
- Wisconsin homicide by intoxicated use convictions under § 940.09
- Wisconsin OWI causing injury convictions under § 940.25
- Out-of-state convictions, suspensions, and revocations for offenses "substantially similar" to a § 346.63(1) Wisconsin OWI
The standard Illinois DUI conviction under 625 ILCS 5/11-501 meets the substantially-similar test and counts as a Wisconsin prior. The nuance is in the dispositions that look similar but legally are not.
What counts vs. what doesn't (Illinois dispositions)
| Illinois disposition | Wisconsin treatment under § 343.307(1) |
|---|---|
| 625 ILCS 5/11-501 DUI conviction | Counts. Substantially similar to § 346.63(1) Wisconsin OWI. |
| 625 ILCS 5/11-501.1 statutory summary suspension | Often counts as a "suspension" under § 343.307(1), particularly when paired with a refused or failed chemical test. Fact-specific audit required. |
| 730 ILCS 5/5-6-3.1 court supervision (successfully completed) | Often does NOT count. Court supervision is a non-conviction disposition; if completed successfully, the underlying DUI charge is dismissed. Audit on every case to confirm. |
| 625 ILCS 5/11-503 reckless driving (reduction from DUI) | Does NOT count. Illinois reckless driving is not "substantially similar" to a Wisconsin § 346.63(1) OWI. |
| Illinois "wet reckless" plea | Mixed. Whether a wet-reckless plea (reckless driving + reference to alcohol) is substantially similar to OWI is fact-specific and not uniformly resolved. Audit required. |
The lookback window matters
The 10-year window only applies at the 2nd-offense Wisconsin tier. For a charged 3rd, 4th, 5th, 6th, 7th, 8th, 9th, or 10th-or-subsequent Wisconsin OWI, every qualifying Illinois DUI prior back to January 1, 1989 counts. A 1992 Illinois DUI conviction is the same as a 2024 one for charging a Wisconsin 4th-offense Class H felony.
This is the single most common misunderstanding among Illinois clients: the "fresh start" or "clean for 10 years" assumption is correct only for the 2nd-offense tier. Above that, the lookback is effectively lifetime.
Why the Illinois-prior audit is high-leverage
Striking a single Illinois prior drops the Wisconsin charging tier:
- 2nd → 1st: removes mandatory 5-day jail, $350-$1,100 fine, 12-18 month revocation, IID. Wisconsin is the only state where the 1st offense is a civil forfeiture rather than a misdemeanor; this drop eliminates the criminal record entirely.
- 3rd → 2nd: removes mandatory 45-day jail, eliminates BAC enhancement under § 346.65(2)(g), shortens revocation.
- 4th → 3rd: removes the felony designation entirely. Eliminates lifetime federal firearm ban (18 U.S.C. § 922(g)(1)), voting rights suspension, and immigration consequences.
- 5th → 4th: drops a Class G felony (max 10 years) to a Class H felony (max 6 years). Removes 18-month mandatory initial confinement.
Defense workflow on Illinois priors
- Obtain certified records from the Illinois county circuit court that handled the original DUI. The Illinois Secretary of State driving record summary is not sufficient; we need the underlying court file.
- Audit the disposition. Was it a 625 ILCS 5/11-501 conviction, a court supervision under 730 ILCS 5/5-6-3.1, a reduced reckless driving, or a statutory summary suspension only?
- Check the date. For 2nd-offense Wisconsin charging, is the Illinois prior inside or outside the 10-year window measured from the Wisconsin offense date?
- Audit the underlying plea. Was the defendant represented by counsel? Was the plea voluntary and informed? An uncounseled prior that resulted in jail cannot be used for sentence enhancement under Nichols v. United States, 511 U.S. 738.
- File the motion to strike. The state bears the burden of proving each prior. A successful strike drops the Wisconsin tier.
By the numbers: Wisconsin / Illinois cross-state OWI traffic
- 22,145 Illinois DUI arrests in 2024 (Illinois Secretary of State, 2025 Illinois DUI Fact Book). Companion data: "90% of all eligible drivers arrested for DUI lost their driving privileges" via statutory summary suspension; court dispositions = 35% DUI conviction / 61% court supervision / 4% other.
- 25,066 Wisconsin OWI convictions in 2024 (WI DOT). For Illinois drivers crossing into Wisconsin and getting an OWI, this number represents the prosecution-side counterpart to Illinois's own 22,145 DUI arrests.
- Court supervision is the most common Illinois DUI disposition (61%) and a meaningful share of those dispositions, when successfully completed, do NOT cross-count as a Wisconsin OWI prior under § 343.307(1). The audit at the start of every Wisconsin case with an Illinois history examines what the underlying disposition actually was.
Sources: Illinois Secretary of State 2025 Illinois DUI Fact Book · WI DOT Traffic Convictions 10-year summary
Border-county OWI is our daily practice. Pleasant Prairie, Twin Lakes, Lake Geneva, Fontana, and the I-94 corridor through Kenosha County see a high volume of Illinois-resident OWI defendants. We audit every Illinois prior on day one and coordinate with Illinois counsel when the home-state consequences matter. Call (262) 632-5000 24/7. Hablamos español. For the broader two-state strategy framework, see our out-of-state driver guide.
