Safety Expert Witness Testimony in Parking Lot Slip-and-Fall Cases
A safety expert may testify in a store parking lot slip-and-fall case when specialized knowledge would help the judge or jury understand a disputed condition and the testimony satisfies applicable qualification, reliability, and admissibility requirements.
Some conditions can be evaluated through photographs, witness testimony, maintenance records, and ordinary experience. Others may call for measurements, technical standards, specialized testing, or engineering analysis.
This guide explains what a parking lot safety expert may analyze, when expert testimony may be necessary, and how courts evaluate admissibility under Federal Rule of Evidence 702.
What Does a Parking Lot Safety Expert Analyze?
The appropriate expert depends on what allegedly contributed to the fall. A safety professional, engineer, slip-resistance specialist, human factors expert, or other qualified professional may evaluate issues such as:
- Pavement deterioration, cracks, potholes, or changes in elevation.
- Surface slope and drainage.
- Water accumulation, ice, snow, or de-icing practices.
- Lighting and visibility.
- Pedestrian routes, curbs, ramps, and accessible areas.
- Warnings or other hazard-control measures.
- Inspection, maintenance, and repair practices.
- Slip resistance when surface traction is genuinely disputed.
A qualified expert may compare observed conditions with applicable codes, standards, technical principles, or documented industry practices that relate to the disputed issue.
The expert's role is not to decide whether the store was legally negligent. Instead, the expert can explain technical findings that may help the factfinder evaluate disputed issues.
Choosing the Appropriate Expert Discipline
The disputed condition should guide expert selection because the label "safety expert" can cover several disciplines.
A civil or safety engineer may be appropriate for pavement, slope, drainage, or design issues. Surface traction and testing may call for a qualified slip-resistance specialist. A lighting or human factors professional may be useful when visibility requires specialized analysis. Snow-and-ice management expertise may be appropriate when winter maintenance practices are central to the dispute.
Attorneys should consider whether the expert's education, training, experience, and methodology match the opinions the expert will be asked to offer.
What Evidence May a Safety Expert Review?
Expert analysis should generally be based on evidence about the conditions involved in the incident. Depending on the dispute, an expert may review:
- Photographs and video from the accident scene.
- Surveillance footage.
- Incident reports.
- Inspection and maintenance records.
- Repair histories and work orders.
- Parking lot plans, surveys, and construction documents.
- Snow and ice removal contracts or logs.
- Weather information when relevant.
- Lighting measurements or fixture information.
- Drainage features and surface elevations.
- Measurements from a site inspection.
- Slip-resistance testing when appropriate.
Parking lots may be resurfaced, patched, restriped, or otherwise altered after an incident. Photographs and records from around the time of the event may therefore be especially important when the original condition can no longer be examined.
Which Safety Standards May Apply to a Store Parking Lot?
The legal requirements for a customer parking lot depend on the condition at issue and the governing jurisdiction. State or local rules and accessibility requirements may apply, while site-specific design criteria and recognized technical standards may also inform the analysis.
The Americans with Disabilities Act may be relevant when a dispute involves accessible parking spaces, access aisles, or accessible routes. Where applicable, the 2010 ADA Standards address accessible routes and the surfaces and slopes of accessible parking spaces and access aisles.
OSHA serves a different purpose. The Occupational Safety and Health Act concerns occupational safety and health, and the construction standards in Part 1926 apply to employees engaged in construction work. Those provisions should not automatically be treated as the legal standard for a retail customer's parking lot accident.
An expert should explain why any cited code, standard, or guideline applies to the disputed condition.
When Is Technical Testing Useful?
Technical testing can be useful when a disputed condition cannot reliably be evaluated through ordinary observation.
For example, slip-resistance or coefficient-of-friction testing may help when a party contends that a wet surface provided inadequate traction. Reliability may depend on the testing method, testing conditions, and how closely those conditions reflect the circumstances relevant to the incident.
Under Rule 702, credentials alone are not enough. The testing and resulting opinion must also satisfy the rule's reliability requirements.
When Might an Expert Not Be Necessary?
Not every parking lot fall requires expert testimony. Some issues, such as whether a visible obstruction or warning sign was present, may fall within a juror's ordinary experience. Whether an expert is required depends on the claim, disputed condition, and governing jurisdiction.
In Bunting v. District of Columbia CVS Pharmacy, LLC, the United States Court of Appeals for the District of Columbia Circuit held, under District of Columbia law and the theory presented, that expert testimony was needed to address whether a walkway's coefficient of friction made it dangerously slippery.
Beyond expert testimony addressing whether the walkway was dangerously slippery, the court stated that no further expert testimony was required for jurors to understand the issues pertaining to CVS's duty of care under the circumstances. The court did not decide CVS's alternative notice argument and left Rule 702 admissibility questions for the district court on remand.
The decision illustrates why the need for an expert should be tied to the particular technical issue rather than assumed in every slip-and-fall case.
Federal Rule of Evidence 702 and Safety Expert Testimony
In federal civil proceedings governed by the Federal Rules of Evidence, Rule 702 sets the principal qualification and admissibility requirements for expert testimony. The proponent must show that it is more likely than not that the rule's requirements are satisfied.
Among other requirements, the testimony must:
- Help the trier of fact understand the evidence or determine a fact in issue.
- Be based on sufficient facts or data.
- Be the product of reliable principles and methods.
- Reflect a reliable application of those principles and methods to the facts.
The 2023 amendment clarified that the proponent must establish these admissibility requirements by the more-likely-than-not standard. Once that threshold is met, some remaining objections may concern weight rather than admissibility.
In Daubert v. Merrell Dow Pharmaceuticals, Inc., the Supreme Court described the federal trial court's gatekeeping role for relevant and reliable scientific expert testimony. Kumho Tire Co. v. Carmichael confirmed that this obligation also applies to technical and other specialized expert testimony.
Attorneys litigating in state court should confirm the evidentiary rules and precedent governing the jurisdiction.
Common Challenges to a Parking Lot Safety Expert
A safety expert may be challenged based on qualifications, methodology, factual foundation, relevance, or the scope of the opinions offered.
Common issues include whether:
- The expert has relevant experience with the specific condition being evaluated.
- Testing used a reliable methodology that was properly applied.
- Conditions during later testing sufficiently resemble those at the time of the incident.
- The expert identified the standards or technical principles relied upon.
- The expert considered important contrary evidence.
- The conclusions extend beyond what the measurements or methodology can reliably support.
- The testimony addresses a matter requiring scientific, technical, or other specialized knowledge rather than merely telling the jury how to decide an issue within ordinary experience.
Qualifications alone do not establish admissibility. Rule 702 also requires an adequate factual basis, reliable methodology, and reliable application to the facts.
