Who Is at Fault for a Single-Vehicle Accident?

September 30, 2025 | Car Accidents

Accidents involving only one vehicle may seem straightforward, but determining who is at fault can be complicated. In Pennsylvania, as in many other states, a single-vehicle accident can involve various factors that influence liability, such as road conditions, driver behavior, and even vehicle maintenance. 

If you or a loved one has been involved in a single-vehicle accident, understanding the factors that contribute to these accidents can help you know your rights and responsibilities.

Common Causes of Single-Vehicle Accidents

To understand fault, it’s crucial to examine the common causes behind single-vehicle accidents. Sometimes, the cause may be entirely the driver’s fault, but in many cases, outside factors could contribute to the accident.

Driver Error

The majority of single-vehicle accidents are caused by driver error. 

Some of the most common driver-related causes include:

• Speeding: Going too fast for road conditions or exceeding the speed limit can cause a driver to lose control of their vehicle.
• Distracted Driving: Texting, talking on the phone, or engaging in other distractions can impair a driver’s ability to respond to road hazards.
• Driving Under the Influence (DUI): Alcohol and drugs significantly impair a driver’s ability to operate a vehicle, leading to accidents.
• Fatigue: Drowsy driving is as dangerous as driving under the influence of alcohol or drugs.

These actions can often be easily traced to the driver, making them the likely person at fault.

Poor Road Conditions

Sometimes, the condition of the road can be a major factor in a single-vehicle accident. Potholes, wet or icy surfaces, and poorly marked roads can cause a vehicle to lose control. While the driver may be at fault for not adjusting their driving to the conditions, the entity responsible for maintaining the road could share some liability. 

In Pennsylvania, the state government and local municipalities are generally responsible for maintaining the safety of public roads. If poor road conditions contributed to the accident, the government agency in charge of maintaining that road could be held partially liable.

How Fault Is Determined in Pennsylvania

In Pennsylvania, fault in a single-vehicle accident is determined by reviewing the circumstances surrounding the crash. Insurance companies, law enforcement, and legal professionals will consider several factors when determining who is responsible for the accident.

The Role of Police Reports

When an accident occurs, the police typically arrive at the scene to investigate the incident. Their report may include important details about the cause of the accident. They will document details such as road conditions, weather, and witness statements. 

However, the police report alone is not always definitive in determining who is at fault. While it can be helpful, it’s not the final word in determining liability.

Insurance Investigation

After the police report is filed, the insurance company will launch its own investigation into the accident. The insurance adjuster will review the police report, vehicle damage, witness statements, and any other relevant evidence to determine who is liable for the accident. 

In some cases, the driver’s own actions—such as failing to yield or driving under the influence—can result in the driver being held responsible.

Comparative Negligence

Pennsylvania follows a comparative negligence rule, which means that fault can be divided between multiple parties. Even if the driver is partially at fault, they may still be eligible for compensation, but the amount will be reduced based on their percentage of fault. 

For example, if the driver was speeding but also faced a hazardous road condition, both the driver and the road authority may share some responsibility.

Call Our Harrisburg Car Accident Lawyers for a Free Consultation

When it comes to a single-vehicle accident in Pennsylvania, determining fault is not always as clear-cut as it may seem. Factors such as weather, road conditions, and vehicle maintenance issues can all help narrow down who may be liable for the crash. 
By working with a knowledgeable car accident lawyer, you can better understand how fault is determined and ensure that your rights are protected as you navigate the aftermath of the accident.

Call Marzzacco Niven & Associates to schedule a free consultation today.

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