St. Louis County, MO — June 15, 2025, One person was injured following an 18-wheeler accident that occurred at around 9:45 A.M. on I-44.

According to official reports, a Nissan Altima was traveling east on Interstate 44 when for unknown reasons it traveled across all lanes of traffic and struck a parked 18-wheeler on the right shoulder of the highway.

When first responders arrived on the scene they found the Nissan driver seriously injured and transported them to the hospital for treatment, and their current condition has not been disclosed. This remains an ongoing investigation.

Commentary by Attorney Michael Grossman

When people see that a car veered across an entire highway and struck a parked 18-wheeler on the shoulder, the first question is usually: What on earth could cause that? Most folks assume that the truck being parked off the roadway means the situation is cut-and-dried. But in my experience, these kinds of crashes are rarely that simple.

At this stage, we’re told the Nissan Altima crossed all lanes of traffic before hitting the parked 18-wheeler. But the reason for that sudden lane departure hasn’t been made public. That leaves us with a critical unknown: Why did the car cross the roadway in the first place?

The Vehicle's Movement Is Only Half the Story

There are all kinds of reasons a driver might swerve or drift across lanes—medical emergencies, fatigue, distraction, mechanical issues, or trying to avoid something on the road. Without more evidence, there’s no way to know whether this was a driver-related issue, a vehicle malfunction, or even something environmental, like debris or glare.

That’s why any meaningful investigation needs to go beyond the crash scene. Investigators should be looking at the car’s event data recorder (if it has one), phone records, and possibly toxicology tests. That data can tell us whether the driver tried to brake, steer, or correct course—or whether they never had a chance.

Was the 18-Wheeler Legally Parked?

Just because a truck is on the shoulder doesn’t automatically mean it was parked legally or safely. Was the truck disabled or stopped for another reason? Did the driver put out the required reflective triangles or hazard lights? I’ve handled cases where parked trucks on the shoulder played a much bigger role in a crash than people initially thought—especially at night or in poor visibility conditions.

In one case, a truck driver pulled off on the shoulder to rest and never deployed warning devices. Another driver who veered off the road never saw the trailer until it was too late. In that case, a jury found that even though the injured driver was partially responsible, the trucking company still bore significant blame for how and where that truck was parked.

Whether something similar applies here remains to be seen. But it’s a mistake to assume the truck's presence on the shoulder removes it from the equation.

Key Takeaways

• Authorities have not yet disclosed why the Nissan crossed all lanes of traffic before striking the truck.
• Distraction, fatigue, mechanical failure, or evasive action are all possible causes that require investigation.
• The legality and safety of the truck’s position on the shoulder should be closely examined.
• Evidence like black box data, dash cams, and warning device usage can help clarify the role of each vehicle.
• It’s too early to assign fault until more information is gathered and analyzed.