Long Island Truck Underride
Accident Lawyer

Legal Analysis

Rear vs. Side Underride: Two Different Crashes, Both Preventable

Truck underride accidents fall into two primary categories, each with distinct causes, applicable regulations, and liable defendants. Understanding the difference is essential to building the correct legal theory — and identifying every source of liability and insurance coverage available to a seriously injured victim or their surviving family.

Rear underride accidents occur when a passenger vehicle traveling behind a tractor-trailer strikes the rear of the trailer and slides underneath it. The most common scenario: the trailer stops suddenly (or was stopped in a travel lane), and the following vehicle cannot stop in time. Because the trailer sits roughly 4 feet above the ground — well above the height of a passenger car hood — the front of the car passes under the trailer body while the trailer frame contacts the windshield, roof, and A-pillars directly. Every protective structure in the vehicle is bypassed. The result is decapitation, crush injuries to the head and torso, and fatalities at crash speeds as low as 35 mph. Federal regulations under 49 CFR §393.86 and FMVSS 223/224 (49 CFR §571.223 and §571.224) exist specifically to address this hazard by requiring rear impact guards of sufficient height, width, and structural strength to absorb the impact and prevent the vehicle from sliding under.

Side underride accidents occur when a passenger vehicle strikes the side of a trailer — most commonly when the truck is making a wide turn, changing lanes, or when the trailer is parked or drifting across a lane. The side of a trailer presents the same lethal geometry: the vehicle hood passes under the trailer frame, and the roof of the passenger compartment contacts the undercarriage. Unlike rear underride crashes, side underride guards are not currently mandated by federal regulation for most trailers. But the absence of a federal mandate does not eliminate liability: carriers and trailer owners can be held liable under common law negligence for failing to equip their trailers with side guards where the risk was foreseeable and the technology was available. For a broader view of how these crashes fit within truck accident litigation on Long Island, see our Long Island truck accident lawyer page.

Both rear and side underride accidents produce the most catastrophic injuries seen in motor vehicle collision cases on Long Island: traumatic brain injuries, spinal cord injuries at the cervical level, crush injuries to the chest and abdominal organs, amputations, and fatalities. These outcomes are not accidents in any true sense — they are the foreseeable result of engineering failures and regulatory non-compliance that the law requires carriers and manufacturers to prevent.

Federal Regulations Governing Underride Guards

The federal regulatory framework for underride guard safety is found primarily in Title 49 of the Code of Federal Regulations and the Federal Motor Vehicle Safety Standards. Violations of these regulations are central to building a strong underride accident claim — they establish negligence per se and set the evidentiary foundation for expert testimony on guard defect.

49 CFR §393.86 requires rear impact guards on most trailers with a gross vehicle weight rating over 10,000 pounds. The regulation specifies precise dimensional requirements: the guard must extend horizontally across the full width of the trailer to within 4 inches of each side; it must be positioned so that its lower edge is no more than 22 inches above the ground when the trailer is empty; and it must be constructed to withstand the loads specified in the FMVSS. A guard that is too high, too narrow, improperly mounted, or missing entirely is a per se violation of federal law — and that violation is evidence of negligence in a New York civil court.

FMVSS 223 (49 CFR §571.223) establishes performance requirements for rear impact guard components themselves. FMVSS 224 (49 CFR §571.224) governs rear impact protection for trailers and semi-trailers — specifying that the rear impact guard must withstand a 50,000-pound force applied at the center of the guard and a 25,000-pound force applied at test points 12 to 18 inches from each end. A guard that buckles, separates, or fails to prevent vehicle intrusion at crash speeds consistent with normal highway driving has, in almost every case, failed to meet these standards. Our engineers perform post-crash inspection and load testing to document the failure mode and quantify the deviation from the required specification.

49 CFR §393.11 requires that trailers be equipped with reflective conspicuity tape and lighting that outlines the trailer’s profile in low-visibility conditions. A parked or slow-moving trailer without required conspicuity markings is effectively invisible at night — and the failure to maintain required lighting and reflective tape is an independent basis for liability against the carrier when a victim’s vehicle strikes an unlit trailer.

Beyond regulatory violations, underride guard cases also proceed under strict products liability pursuant to the Restatement (Second) of Torts §402A. A guard manufacturer who places a defective product into the stream of commerce is strictly liable for injuries caused by that defect, regardless of whether the manufacturer acted with reasonable care. This theory runs parallel to and independently of the carrier’s negligence claim — opening an entirely separate line of recovery against the manufacturer’s insurance. For related product defect claims in vehicle accidents, see our Long Island defective vehicle accident lawyer page.

Multiple Defendants, Multiple Policies: How Underride Cases Are Different

One of the defining features of truck underride accident litigation — and one reason why maximum recovery frequently exceeds what a standard car accident claim could yield — is the number of potentially liable defendants and the corresponding number of insurance policies available for recovery.

The truck driver may be liable for negligent operation: stopping in a travel lane, failing to activate hazard lights, making an unsafe turn, failing to maintain a safe following distance, or driving while fatigued. The carrier (trucking company) is vicariously liable for the driver’s conduct under respondeat superior when the driver was acting within the scope of employment, and bears independent liability for negligent hiring, negligent training, failure to inspect and maintain underride guards, and failure to ensure FMCSA regulatory compliance. Carriers operating interstate commerce are required to carry substantial federal minimum insurance coverage under 49 CFR Part 387.

The trailer owner — which may be a leasing company, a shipper, or a different entity from the carrier — may bear its own maintenance and inspection obligations for the underride guard. The guard manufacturer faces strict products liability for a defectively designed or manufactured guard. The trailer manufacturer may be liable if the trailer’s design created the risk of underride or if the guard mounting system was defective.

Our firm conducts a comprehensive corporate and regulatory investigation from day one: pulling FMCSA safety records and carrier safety ratings, examining DOT inspection histories for prior guard violations, identifying corporate ownership chains for the truck and trailer, and reviewing the guard’s supply chain to identify every manufacturer and distributor with potential liability. This investigation often uncovers prior violations — the same carrier cited for non-compliant guards on previous inspections, or the same guard model subject to prior complaints — that dramatically increase settlement value and punitive damages exposure. For context on how truck accident litigation works across the full range of tractor-trailer crashes on Long Island, see our Long Island truck accident lawyer page.

What Damages Can You Recover in an Underride Accident Case?

Truck underride accidents produce the most severe injuries in motor vehicle litigation. Recovery in these cases is commensurate with the catastrophic nature of the harm — and the availability of commercial insurance policies covering carriers, manufacturers, and trailer owners means the ceiling on available recovery is substantially higher than in a typical car accident claim.

Economic damages cover measurable financial losses: all past and future medical expenses (emergency care, neurosurgery, spinal surgery, intensive care, long-term rehabilitation, assistive devices, home modifications, and projected future care needs); past and future lost wages and loss of earning capacity (including the full lifetime economic impact of catastrophic disability); property damage to the vehicle; and all out-of-pocket expenses attributable to the accident and recovery. Future economic losses in catastrophic underride cases — particularly TBI and spinal cord injury cases — regularly reach seven figures when properly calculated with life care planners and vocational economists.

Non-economic damages — pain and suffering, physical disability, loss of enjoyment of life, emotional distress, and loss of consortium — are not capped in New York personal injury cases. They are, however, subject to the serious injury threshold under Insurance Law §5102(d). In underride accident cases, the serious injury threshold is almost always satisfied by the injuries themselves: TBI satisfies the permanent loss or permanent consequential limitation categories; spinal cord injuries, amputations, and fractures satisfy the fracture category; and in wrongful death cases, the EPTL §5-4.1 wrongful death action and conscious pain and suffering claim both proceed without a threshold barrier.

Under CPLR §1411, New York’s pure comparative negligence rule, your recovery is reduced proportionally by your percentage of fault but is not eliminated. Defense counsel in underride cases will often argue that the victim was speeding or following too closely — our firm uses regulatory violation evidence and expert reconstruction to demonstrate that a properly maintained, code-compliant guard would have prevented the injury regardless of the precise crash speed.

For product liability claims where the guard manufacturer is a defendant, CPLR §214-c provides a three-year statute of limitations running from the date of discovery of the injury or its cause — which can extend the filing window in cases where the defective nature of the guard was not immediately apparent. Product defect claims against manufacturers can also support punitive damages where the manufacturer had prior knowledge of the defect and failed to recall or redesign the product. For more on how product defect law applies to vehicle component failures, see our Long Island defective vehicle accident lawyer page.