Traffic offenses and DWI in Texas: what the statutes lay out

This guide describes Texas driving law at two levels: the everyday rules of the road in the Transportation Code, and the intoxication offenses of Penal Code chapter 49 — what "driving while intoxicated" means, how the offense is graded, and how prior convictions raise it. It explains what the statutes say and how the Court of Criminal Appeals has read them; it is not legal advice. Every section and case discussed here links to the full text hosted in this library.

Informational only — not legal advice. This page describes statutes and court opinions; it does not apply them to any situation. Verify every section against the official Texas statutes ↗. Driver's licensing and administrative license suspension (Transportation Code chapters 521, 524, and 724) are not hosted in this library; their official text is at the same site ↗.

The governing law at a glance

The offense, step by step

1. The traffic stop. Most DWI cases begin as traffic cases. Chapter 545 supplies the observable violations — § 545.351's command that an operator "may not drive at a speed greater than is reasonable and prudent," § 545.352's posted prima facie limits, § 545.401's reckless-driving standard — and § 601.051 states the financial-responsibility requirement behind insurance citations. These sections describe offenses; the procedures for citations and arrests live elsewhere in the Transportation Code and the Code of Criminal Procedure, not all of which is hosted here.

2. The offense. § 49.04(a) states the crime in one sentence: "A person commits an offense if the person is intoxicated while operating a motor vehicle in a public place." Each noun carries an element: intoxicated (defined in § 49.01), operating (undefined in the statute — the courts' territory, as Kuciemba shows), motor vehicle, and public place.

3. "Intoxicated." § 49.01(2) defines the term two ways: "(A) not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug … or any other substance into the body; or (B) having an alcohol concentration of 0.08 or more." Subsection (1) fixes what "alcohol concentration" means per unit of breath, blood, and urine. How the two definitions relate to the charge was the question in Barbernell.

4. Grading. § 49.04(b)–(d) grades the base offense a Class B misdemeanor with a 72-hour minimum term, raises the minimum with an open container "in the person's immediate possession," and makes the offense a Class A misdemeanor when the specimen shows a concentration of 0.15 or more. § 49.11 adds a structural feature the Court of Criminal Appeals relied on in Lomax v. State, 233 S.W.3d 302 (Tex. Crim. App. 2007): no culpable mental state is required for chapter 49 offenses.

5. License consequences. A DWI arrest also triggers administrative license-suspension machinery under Transportation Code chapters 524 and 724 (implied consent) — not hosted in this library; official text at statutes.capitol.texas.gov ↗.

6. Enhancement. § 49.09 raises the grade by history: one prior "offense relating to the operating of a motor vehicle while intoxicated" makes the offense a Class A misdemeanor with a 30-day minimum; two priors make it a third-degree felony — "felony DWI," the offense at issue in Benson.

7. Injury and death. When intoxicated operation causes serious bodily injury "by reason of that intoxication," § 49.07 (intoxication assault) applies; a death by accident or mistake is § 49.08 (intoxication manslaughter). How these interlock with felony DWI for double-jeopardy purposes is Benson's subject.

The key sections, closely read

**§ 49.01(2) — the two definitions.* The impairment definition (A) reaches any introduced substance and speaks of "normal use of mental or physical faculties"; the per se definition (B) is purely numerical. As Barbernell explains, the State may prove either; the definitions describe means of committing* one offense, not separate offenses.

**§ 49.09 — enhancement.** The section works entirely through prior convictions "shown on the trial of the offense": one qualifying prior lifts the grade to Class A; two lift it to a third-degree felony. The qualifying priors are not limited to car cases — the text enumerates intoxicated operation of aircraft, watercraft, and amusement rides — and later subsections govern when older convictions count and how the priors interact with the intoxication-assault and manslaughter offenses.

How the courts have read it

The opinions below — all from the Texas Court of Criminal Appeals — are hosted in this library in full; each links to its authoritative source from its own page. They construed the versions of the statutes in force when decided.

State v. Barbernell, 257 S.W.3d 248 (Tex. Crim. App. 2008)

• Issue — Whether a DWI charging instrument must specify which of § 49.01(2)'s two

definitions of "intoxicated" — impairment or the 0.08 per se standard — the State intends to prove.

• Holding — The court held that "the definitions of 'intoxicated' do not describe an act or

omission" but rather the means of commission, so the charging instrument need not allege a particular definition; it reversed the court of appeals, which had upheld quashing the information.

• Turns on — § 49.01(2) (the two definitions); § 49.04 (the offense they

plug into).

• Connects — Settles how the definitional element travels through a case: the two definitions

are alternative routes to one element, which is why breath-test evidence and impairment observations can both matter in the same trial — the pairing Diagram B depicts.

• Read it — Full opinion in this library.

Kuciemba v. State, 310 S.W.3d 460 (Tex. Crim. App. 2010)

• Issue — A driver was found intoxicated (a 0.214 specimen) at the scene of a single-car

rollover, with no witness to the driving and no direct evidence of when the crash happened. The court of appeals held the State failed to prove the temporal link — that the driver was intoxicated "while" driving.

• Holding — The court held the circumstantial evidence sufficient: being intoxicated at the

scene of a one-car accident the defendant was driving supports the inference "either that appellant was recently involved in the accident or that he had been intoxicated for quite a while," and the combination sustained the conviction. It reversed the court of appeals.

• Turns on — § 49.04(a) (the "intoxicated while operating" element and its temporal

connection).

• Connects — The leading statement of how the operation element can be proved without an

eyewitness — the element Barbernell's definitions feed into, established here entirely by circumstance.

• Read it — Full opinion in this library.

Ex parte Benson, 459 S.W.3d 67 (Tex. Crim. App. 2015)

• Issue — After one crash seriously injured one person, the defendant was convicted of both

intoxication assault (§ 49.07) and felony DWI (§ 49.04 enhanced by § 49.09). The question was whether the two are "the same offense" for double-jeopardy purposes when they arise from the same transaction.

• Holding — The court held "that they are not": intoxication assault and felony DWI have

distinct elements — one turning on causing serious bodily injury by reason of intoxication, the other on the fact of two prior intoxication convictions — so both convictions could stand.

• Turns on — § 49.07 (intoxication assault); §§ 49.04 and 49.09 (felony

DWI as defined by the base offense plus two priors).

• Connects — Shows the enhancement and injury branches of the flow diagram operating at once,

and states precisely what § 49.09's priors are: an element of felony DWI, not merely a sentencing fact.

• Read it — Full opinion in this library.

Evidence and elements

The map above pairs each statutory element with the kinds of evidence the courts in the linked cases discussed — specimen results measured against § 49.01's per se definition and officer observations against its impairment definition (both routes Barbernell holds available); scene and crash evidence supplying the circumstantial temporal link to operation that Kuciemba found sufficient; and judgments of prior convictions, which under § 49.09 — as Benson explains — function as elements of felony DWI. The map describes what those opinions examined; it is not a checklist for any particular situation.

Where to verify

• Official statute text: statutes.capitol.texas.gov ↗ —

including Transportation Code chapters 521 (driver's licenses), 524 and 724 (administrative license suspension and implied consent), and 543 (arrests and citations), which this library does not host.

• In this library: Penal Code chapter 49 · Transportation Code chapter 545 ·

chapter 601.

• Every case page above carries its own hand-off link to the authoritative source of the opinion.