Slip resistance and walkway safety expert

Expert class library · Personal injury · Either side

Tests the slipperiness of floors and walkways and explains whether the surface, maintenance or contaminants made a fall foreseeable.

What this expert is retained to answer

• What instrument measured the coefficient of friction, was it validated and calibrated, and was it used as the manufacturer intended?
• Where and when were the tests run, and how close were they to the spot and the conditions of the fall?
• Which standard sets the threshold the expert applies, and does it govern this kind of surface?
• Has the surface or contaminant changed between the fall and the testing, and how does the expert account for that?
• Does the opinion go beyond the tested area, for example to how the whole floor would feel to someone walking across it?

Methods

• Tribometer testing (variable incidence tribometer, BOT-3000E)
• ASTM F2508 validation and ANSI A326.3 comparison
• Floor maintenance program review
• Contaminant analysis
• Testing timing and location relative to the fall

How the testimony is attacked

• Testing long after the fall. Defendants argue that readings taken months later say nothing about the floor on the day of the fall. In Sorrels v. NCL (Bahamas) the Eleventh Circuit held that a year and a half gap did not by itself make the readings unreliable absent evidence the surface had changed, and reversed their exclusion.
• Untested areas. Opponents attack opinions about parts of the surface the expert never measured. Sorrels affirmed exclusion of a false sense of security theory because the expert had not tested along the path the plaintiff walked before slipping.
• Inapplicable standard. Challengers argue that the cited standard does not govern the surface at issue. In Sorrels the court of appeals held that the district court erred in treating the expert's reliance on a shipboard walking surface standard as a ground for excluding his testing.
• Instrument, calibration and protocol. Parties attack calibration and use of the tribometer. In Bunting v. District of Columbia CVS Pharmacy the court found variable incidence tribometer testing on an ASTM F2508 validated device, calibrated days before the test, reliable, and treated remaining calibration disputes as weight.
• Testing a substitute surface. Defendants argue the expert tested an exemplar rather than the actual floor. In Barnes v. Malinak the court left to cross-examination an expert's use of a representative test tile to measure a bath mat's friction when he had not inspected the actual floor.

What the public record shows

A deliberately narrow CourtListener search, (slip* AND (coefficient OR tribometer OR "slip resistance")) AND expert AND (Daubert OR "Rule 702"), returned 26 opinions filed since 2015, as of October 3, 2026; broader searches return more. Three that show how courts handle this class of testimony:

Each case links to the free opinion text on CourtListener.

Under amended Rule 702

Since December 1, 2023, Rule 702 says expressly that the party offering an expert must show the court it is more likely than not that the testimony meets each requirement: that it rests on sufficient facts or data, uses reliable methods, and reflects a reliable application of those methods to the case. Questions about the basis of an opinion are no longer automatically matters of weight for the jury. For how the circuits have applied the amendment, see the Rule 702 tracker, which follows each court of appeals; for what that means for preparing or attacking this class of expert, see the guide on amended Rule 702.

Related classes

• Warnings and human factors expert
• Construction defect engineer
• Industry custom and practice expert

Guides

• Amended Rule 702 After Nearly Three Years: What Courts Exclude

Simulating this class on a matter

Supreme Mind simulates a class of expert, never a named individual, on your fact pattern and returns the likely opinion, the ranked cross-examination weaknesses, the Rule 702 attack surface and what it means for settlement. Read how it works, or book a demo.

Last reviewed October 3, 2026. How this page is built: rulings are found by searching court opinions on CourtListener, and each one is read in the opinion before it is summarised here; outcomes are labelled by what the court did with the expert's testimony. No individual expert is named. This page summarises public decisions for orientation and is not legal advice; read the opinion before relying on any ruling.