Slip Resistance for ADA Compliant Walkway: Other Resources

Siegmund, Blanchette, et al. Properly estimating and reporting the uncertainty of walkway surface friction is key to ensuring pedestrian safety. Here we quantified the amount and sources of uncertainty in friction measurements by having four users of four units of each of two walkway tribometer models (Slip-Test Mark IIIB, English XL) perform 12 measurements on four samples of four different surfaces that ranged from slippery to slip-resistant. We found that 51–82% of the total variance in the measurements was explained by the user, unit, sample and a user–unit interaction, which means that the variance a single user calculates from their own data does not capture most of the uncertainty in their measurements. Based on these data, the minimum uncertainty associated with the mean of a user’s measurements is ±0.064 (Mark IIIB) and ±0.072 (XL) to be 95% confident that their mean captures a surface’s available friction. Would need to be requested.

Joganich, Levitan, Cohen. Forensic investigations of slip and fall accidents often entail measuring the slip resistance of the subject floor with tribometers that are often different, which results in expectedly different slip resistance values. Differences in slip resistance measurements obtained on the same floor can be expected when measured with two different tribometers due to the nature of their operation and testing protocol. One such case involved slip resistance testing with two different tribometers using disparate protocols. The measured slip resistance values were substantially different from each other beyond what would be intuitively expected. Nevertheless, specious comparisons were made in this case between the slip resistance values that were measured with two different tribometers. A preliminary laboratory-based study was conducted to investigate the consistency of the differences in slip resistance measurements across floors, which underscores that the proper interpretation of the slip resistance values must be made within the framework of each tribometer.

Baker. (Thesis). A walkway tribometer measures the coefficient of friction between flooring material and a test foot. The value of the coefficient of friction is an indicator as to whether the flooring surface is slippery and has a propensity to cause slip and falls. This study determined that one style of tribometer, an XL Tribometer, mimics the heel-to-floor interaction of the human heel strike. High speed video studied the impact and speed of heel strikes, The pressure setting was found to have a significant effect on the impact speed while the mast angle had an insignificant affect. A review of human walking studies revealed a range of pedestrian heel impact speeds on the order of 19.4 to 45.3 in/s during normal human ambulation activities. These tribometers fell on the low side of this speed range

Flynn, Di Pilla, Vidal. The measurement of walkway slip resistance is required to assess the risk of slipping. Unlike other countries, the U.S. has not decided upon a single approach to the measurement of slip resistance. Several types of tribometers are available to measure slip resistance however, the measured value of the slip resistance of a given surface has been found to be tribometer specific. The introduction of ASTM International Standard F2508 Standard Practice for Validation and Calibration of Walkway Tribometers Using Reference Surfaces, has produced a method which allows validation of each type of
tribometer and the values generated during testing.

Marpet, 2001. Walkway-safety tribometers (WSTs) are instruments that measure the friction between a test foot and a walkway surface. Different WSTs, because they measure friction in different ways, often give different results in a given situation. This creates ‘marketplace confusion’, which has caused the American Society for Testing and Materials (ASTM) Committee on Standards (COS) to mandate that ASTM Committee F-13 on Safety and Traction for Footwear implement ‘generic’ standards, which do not reference proprietary equipment. A committee appointed by the ASTM Board of Directors, chaired by the incoming ASTM Chairman of the Board, was formed to assist Committee F-13 in this task. This paper presents the evolution of WST standards and discusses progress in the development of a set of ‘generic’ WST standards. Would need to be requested.

Berggård, (Thesis). Pedestrians injured in single-pedestrian accidents on icy and snowy surfaces also experience more serious injuries than pedestrians injured on other surfaces. Thus, there is a clear need for measures to reduce single-pedestrian injuries and improve the safety of walking, without curtailing the activity, year round. A "slip accident" occurs when a person loses his/her balance. An attempt is normally made to recover one's balance, and the person's balance is either recovered or a fall occurs. An injury may be the consequence of such a fall. The most critical phases of the human gait are the heel strike and the toe-off. Various countermeasures can be used .to reduce the risk of a person slipping and sliding when walking outdoors during the wintertime.

Marpet. In United States jurisprudence, Reasonable Certainty is one of the criteria for the admissibility of expert opinion in litigation. One element of establishing Reasonable Certainty can be that the opinion comports with a code requirement, a voluntary-consensus standard, a handbook reference or, in their absence, with Acceptable Practice. From there, and importantly, that the claimed requirement, standard or practice is causally related to the accident under analysis. It has been my experience that many forensic practitioners simply ignore all this, citing for-one-reason-or-another irrelevant code and standards in their desire to give the work the appearance of a mantle of authority. That this is inappropriate is hopefully obvious. Would need to be requested.

Masory. The responsibility of an Expert Witness is to provide the defending attorney or the prosecutor with technical information supporting their argument. In times it is as simple as measuring the temperature of an oven. In others it might involve the review of a design and the figuring out the cause of failure or reconstruction of vehicle accident and the determination of the cause of injuries by simulating the motion of the during the collision. This paper describes a few cases, in which the author served as an expert witness and how they evolve to research activities and eventually propagate to his classes. Includes information regarding slips and falls on walking surfaces.

Nemire, Johnson, Vidal. Walkway codes and standards are often created through consensus by committees based on a number of factors, including historical precedence, common practice, cost, and empirical data. The authors maintain that in the formulation of codes and standards that impact pedestrian safety, the results of pertinent scientific research should be given significant weight. This article examines many elements of common walkway codes and standards related to changes in level, stairways, stair handrails, and slip resistance. It identifies which portions are based on or supported by empirical data; and which could benefit from additional scientific research. This article identifies areas in which additional research, codes, and standards may be beneficial to enhance pedestrian safety. Would need to be requested.

Strautins, Daniel. Many slip resistance testing standards assess the relative safety of flooring materials by specifying a universal minimum threshold expressed as a Slip Resistance Value (SRV); limiting the use within a risk management context. This study contextualises slip related injuries in a simplified risk management strategy to prioritise slip hazards in conjunction with a broad spectrum of health and safety related hazards in an occupational hygiene setting. Four reference surfaces within ASTM F2508 Standard practice for validation and calibration of walkway tribometers using reference surfaces, were tested by five accredited laboratories to AS/NZS 4586:2004 Slip resistance classification of new pedestrian surface materials conducting slip testing with the pendulum friction tester. The results were evaluated and categorised in terms of likelihood to evaluate within a risk assessment matrix along with qualitative descriptors of slipperiness. HTML document