Negligence per se is a doctrine Texas courts use in certain personal injury cases when a defendant violates a safety statute. Instead of arguing about what a “reasonable person” would have done, the statute can supply the standard of care. Texas courts apply negligence per se most often in traffic-safety cases, where drivers already owe a common-law duty to use reasonable care on the roadway.
This matters a great deal in roadside-worker crashes involving tow operators, police, EMS, TxDOT crews or utility trucks – because Texas has a specific “Move Over or Slow Down” rule that is designed to prevent exactly those collisions.
What negligence per se means in Texas
In general terms, negligence per se is the concept that an unexcused violation of an applicable statute can establish the breach element of negligence. The Texas Supreme Court cases describe negligence per se as courts adopting a legislatively imposed standard of conduct as the reasonable-care standard in appropriate cases.
What negligence per se does (and does not) do
Negligence per se can help prove “breach” (the part of law that says “they did something unsafe”). It does not automatically win the case, however. An injured person must still prove:
- the statute applies to the defendant’s conduct,
- the injured person is within the class the statute was meant to protect,
- the type of harm is the kind the statute was meant to prevent,
- the proximate cause (cause-in-fact and foreseeability), and
- actual damages such as serious injuries.
Texas courts also consider policy factors when deciding whether a particular statute should be used as negligence per se in civil cases (not every criminal statute automatically becomes a civil standard).
The Texas “Move Over / Slow Down” law (Transportation Code § 545.157)
Texas Transportation Code § 545.157 requires drivers approaching certain stationary roadside vehicles with activated visual signals to either:
- vacate the lane closest to the vehicle when the roadway has two or more lanes in the same direction, or
- slow down to a speed not exceeding:
- 20 mph below the posted limit when the limit is 25 mph or more, or
- 5 mph when the posted speed limit is less than 25 mph.
Violations of the “move over/slow down” law can carry escalating criminal or civil consequences, including higher penalties if the violation results in property damage or bodily injury.
Which vehicles are covered?
TxDOT’s public guidance summarizes the covered categories (and is useful for juries because it translates the statute into plain language): law enforcement, emergency responders, tow trucks, TxDOT vehicles, utility vehicles, municipal waste trucks, and more – when stopped on the roadside with overhead lights activated.
Texas also expanded the law effective September 1, 2025 to include vehicles driven by animal control officers and parking enforcement employees (per TxDOT’s summary).
How negligence per se applies to “Move Over / Slow Down” crashes
In a roadside-worker injury case, negligence per se arguments often look like this:
- A safety statute exists (Texas Transportation Code § 545.157).
- The defendant violated the statute (did not change lanes when possible and did not reduce speed as required).
- The statute is designed to protect a clearly identifiable group (roadside responders/workers) and prevent a specific type of harm (strikes and collisions near stopped service vehicles).
- The violation proximately caused the injury (for example, the driver failed to move over, struck a tow operator, or forced evasive movement leading to a secondary crash).
If all of those pieces line up, then this statute can do much of the heavy lifting when determining damages and fault.
Common defenses and “excuse” arguments (and how the evidence answers them)
Defendants often argue:
- “I couldn’t change lanes safely.”
Response: In most cases, defendants have the ability to slow down or fully stop while they wait for an opening. Dashcams, traffic footage, witness statements and other pieces of evidence can all be used to show that the driver was impatient, not incapable of moving. - “I didn’t see the lights / didn’t know it applied.”
In traffic and in many other areas, ignorance of the law does not mean innocence. Ultimately, even if the vehicle’s lights are off, drivers still have a duty to be aware of their surroundings.
Why this matters in Houston-area claims
Houston’s high-speed corridors (I-10, I-45, US-59/I-69, Beltway 8, 610) create a recurring risk profile: disabled vehicles, tow operations, TxDOT and utility work, and emergency responses that happen inches from live traffic. “Move Over / Slow Down” is the rule meant to reduce that predictable danger – and a violation can be a clean, jury-friendly liability story when the facts support it.
Contact a Houston Personal Injury Attorney Today
Negligence per se is powerful in Texas personal injury cases when the safety statute directly fits the event. The “Move Over / Slow Down” law is a prime example: it creates a clear behavioral rule (move over or reduce speed), aims to protect a specific group, and targets a specific crash type. When a driver violates § 545.157 and someone is hurt, that violation can become a central pillar of liability.
The Law Offices of Hilda Sibrian have served the Houston community for over 20 years. We can help evaluate fault, preserve key evidence, and pursue claims against every liable party. Hilda Sibrian serves the Houston metropolitan area, including Sugar Land, Missouri City, La Porte, Beaumont, Pasadena, The Woodlands, The Heights, Bellaire, Kingwood, Baytown and of course Houston proper. Call our office today or fill out our online contact form for a free consultation.
