Click for next page ( 23


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 22
22 Improving Safety-Related Rules Compliance in the Public Transportation Industry Figure 3. Reason's Swiss cheese model of accident causation (Reason 1990). numbered as well. The numbering system corresponds to the levels in Figure 3 and Figure 4 as well as the numbers for the root cause questions in the Investigating the Causal and Contributing Factors of Safety-Related Rules Noncompliance section of this chapter. If a close call, incident, or accident involved multiple instances of noncompliance, use the taxonomy to "drill down" the underlying factors for each noncompliant act. Figure 4 presents a diagram of the taxonomy and illustrates its hierarchy. While the categories of Level I are mutually exclusive for a single non- compliant act, subsequent levels are not. It is important to capture as many contributing factors for Levels II through IV as possible so that corrective actions (i.e., barriers) can be implemented to prevent reoccurrence of noncompliance. A table summarizing the elements of each level of the taxonomy follows the description of that level. Level I: Employee Noncompliance Employee actions are the last event in a chain of events that are closest in time and physical prox- imity to an incident that has resulted from rules noncompliance. While these actions most recently contributed to an incident's occurrence, they are only one of several contributing factors. Based on the intention of the employee, an action can be classified as an error (unintentional noncompli- ance) or a violation (intentional noncompliance). Errors and violations can be further classified based on the underlying reasons for the noncompliance. In-depth classifications will provide a better understanding of why the noncompliance occurred as well as aid the identification of the appropriate corrective measures. 1. Intentionality Determining intentionality is key to understanding the reasons behind noncompliance. Inten- tional noncompliance is referred to as a violation, whereas unintentional noncompliance is con- sidered human error. The challenge to distinguishing violations from errors is the willingness of the employee to share this information. In an environment where the employee fears disciplinary action, he or she may not be forthcoming about intentionally violating a rule. Some employees

OCR for page 22
Classifying Noncompliance 23 Figure 4. Levels of the taxonomy. may claim they were unaware of their noncompliance to avoid disciplinary action. As a result, the noncompliant act may be inappropriately categorized as an error. Because errors and violations have distinct factors contributing to them as well as different strategies to mitigate them, wrongly categorizing actions at this level of the taxonomy will not allow the user to identify the actual rea- sons behind the noncompliant act. Nor will the user identify the appropriate corrective measures to prevent similar instances of noncompliance from reoccurring in the future. One transit agency investigated signal noncompliance and found that the event recorder data, specifically speed, was useful for identifying the underlying reasons for these events. The agency

OCR for page 22
24 Improving Safety-Related Rules Compliance in the Public Transportation Industry found that the noncompliant events fell into two speed categories, those occurring at high speed and those at lower speeds. Those that occurred at high speeds were generally attributable to human error (unintentional) often the result of distraction. The reasons for noncompliance at the lower speeds were variable. The transit agency identified that train handling, a skill-based technique error, was sometimes the culprit. At a different transit agency, a root-cause investigation of signal non- compliance showed that the majority of light rail vehicle operators who had violated the stop sig- nal reported that they presumed that the signal would be permissive by the time they reached it. The latter is an example of a violation where the operator engaged in risky behavior due to over- confidence in his or her ability to predict the signal. 2. Errors Human error arises because our brains are organized in a way that allows us to solve prob- lems by processing information automatically (i.e., often without conscious thought) and making educated guesses (i.e., heuristics). While automaticity and shortcuts make us fast and efficient, inevitably we will succumb to error. Much of noncompliance is due to errors we are unaware of until it is too late. Identifying the type of error that occurred will inform an effec- tive mitigation strategy. 2.1 Perceptual Errors Perception is the psychological construct used to describe how people experience their environ- ment with their senses (seeing, hearing, touching, etc.). These errors occur when one experiences something in the environment that is different from reality. Sometimes people hear or see what they expect to experience. Blind spots resulting from the manner in which mirrors are laid out in an oper- ator's workspace can give the illusion that no person or object is near the vehicle. However, another object, vehicle, or person could be in the blind spot and not be detected by the operator. Sometimes, people incorrectly "fill in" missing or degraded information (e.g., signage) or experience illusions that result in the wrong action. 2.2 Skill-Based Errors Skill-based errors often occur during the execution of highly practiced routines in which there is little or no conscious thought required. These errors commonly happen to everyone in everyday life. As such, they should not be considered an anomaly when they happen during work-related activities. Someone who experiences this type of error is not necessarily incom- petent. Rather, the person is so skilled at what he or she does, the work becomes automatic. Some common, everyday examples include intending to drive to the grocery store after work, but then driving home instead because the route home is similar and more frequently trav- eled. Also included are leaving out a step in a task or walking into a room and not remem- bering the purpose for going there. Skill-based errors can be further categorized into slips, lapses, and technique errors. 2.2.1 Slips. Slips refer to the execution of the wrong action during activities when the employee is not consciously aware of his or her action because he or she is so highly skilled. Slips include habit capture errors (the grocery store example above), misordering, repeating or insert- ing erroneous steps in a task sequence; they tend to be errors of commission. For example, a bus maintainer without awareness of his mistake installed an air line that was longer than the origi- nal hose. As a result, the brakes failed while the bus was in service causing the bus to strike the rear of an automobile that was stopped at a red traffic signal. 2.2.2 Lapses. Lapses, often failures of short-term memory, refer to the omission of some part or all of a task. As such, lapses tend to be omission errors. An employee may become dis- tracted by, or sometimes hyperfocused on, a second task or an extraneous situation to the detri-

OCR for page 22
Classifying Noncompliance 25 ment of the primary task. As a result, the employee either forgets where he or she was in the first task sequence, omitting a critical step, or the employee forgets to resume the first task completely. This can occur, for example, when a bus driver becomes so engrossed in passenger relations, he or she may forget to make a scheduled stop. A lapse occurred when an experienced engineer for- got to make sure that the position of the forward/reverse switch on the master control panel was in the correct position before operating the train. 2.2.3 Technique errors. As employees develop their skill set, they acquire their own personal techniques that may differ from employee to employee. These techniques become engrained into how the employee performs his or her job. Technique errors occur when an employee has developed a maladaptive way of performing his or her job. While the techniques may not violate any specific rule, per se, they set employees up for rule noncompliance. Failure to exer- cise defensive driving skills is a good example of this. Employees develop personal driving techniques over the course of many years before they become professional drivers (e.g., bus drivers). While some companies may require defensive driving courses, it is difficult for employees to abandon how they have driven for years with limited time spent in defensive driving training courses. 2.3 Decision-Based Errors Decision-based errors are also unintentional and can be divided into two subcategories: strategy-based and knowledge-based errors. These errors can be thought of as ineffective deci- sions or honest mistakes involving the application of rules. 2.3.1 Strategy-based decision errors. As employees develop experience, they acquire a repertoire of strategies to accomplish different aspects of their jobs. Sometimes an individual chooses the wrong strategy for a situation or misapplies an effective strategy to the wrong situation; this is known as a strategy-based decision error. An example of a strategy-based error occurred when the procedure of a bus maintenance department did not sufficiently describe the actions required to properly construct, route, and secure a steel braided surge tank vent hose. The mechanic followed the procedure to the best of his or her ability, but used a less than ideal method to secure the hose (the method for that part of the procedure was not specifically defined). The result was a bus engine compartment fire. 2.3.2 Knowledge-based decision errors. Other times employees are inexperienced or are unfamiliar with some aspect of their jobs. They may have a limited set of pre-formed plans they can use when performing their job. These employees may have to identify novel solutions to a problem or find themselves in a situation where they have to interpret and execute rarely used or difficult to understand rules. When an employee fails to comply because of a lack of under- standing of a rule or how to execute it, a knowledge-based decision error has occurred. A knowledge-based error occurred when a novice dispatcher was called by a light rail operator faced with a fire in a tunnel. This is a rare occurrence and one for which the rules and proce- dures are somewhat complex depending on which tunnel is involved. The dispatcher had to respond quickly and neglected to activate the fans in the tunnel. The transit agency deter- mined that the dispatcher did not understand the rule because she had inadequate training on emergency procedures. 3. Violations Within the context of this taxonomy, violations, are always intentional, that is, the employee understands the rule and knows how to apply it, but voluntarily chooses not to comply. Many times supervisors and management think that the only reason people violate rules is because of some per- sonal attribute (e.g., risk taker, no respect for rules). While this is sometimes true, particularly in the

OCR for page 22
26 Improving Safety-Related Rules Compliance in the Public Transportation Industry case of egregious violations or criminal acts, many times there are other reasons an employee may violate a rule. These factors include issues with employee supervision and management, environ- ment and ergonomics, as well as problems with organizational culture. The purpose of calling out the factors associated with violations is not to shift blame from the employee to management or other external factors, but to identify all factors that contribute to a violation so that problems at all levels can be addressed to minimize the probability of reoccurrence. 3.1 Egregious and Criminal Acts As a general rule, transit agencies should have a no tolerance policy for criminal acts such as illegal drug use and working while under the influence of drugs and alcohol. Some transit agen- cies now consider cell phone use while on duty to be an egregious act. Each agency must define what qualifies as an egregious act. Caution should be taken not to make this category too broad because the response to these types of noncompliance is zero-tolerance generally resulting in removal from employment. For example, including violations such as speeding in this category is not useful. Speeding may occur because an employee feels pressure from a supervisor to be on time. By categorizing these types of violations in this category, there is no opportunity to identify the supervisory factor. Because of an organization's response (typically termination) to egregious and criminal acts, determining the root cause of such violations is nearly impossible because there is no incentive for the employee to share information. Therefore, in the case of truly criminal acts, foregoing root cause analysis is warranted. Transit agencies can enhance compliance with zero-tolerance policies by educating the employees regarding the risk associated with noncompliance. 3.2 Routine Violations These occur when a shortcut or quicker way to the end goal presents itself and is taken on a reg- ular basis. While the act may be against the rules, employees reason that their skill offsets the pos- sible consequences of or risk associated with the noncompliance. A routine violation occurred when track maintainers were found to regularly forego the application of a redundant shunting device to protect a crew working on the tracks because they believed that protection from the train dispatcher was adequate. 3.3 Exceptional Violations These often occur when employees are faced with unusual circumstances that call for an unusual response (e.g., emergency situations). Often times, the rules or procedures may be inadequate to accommodate the situation. The distinguishing feature between decision-based errors, as they previously are described, and exceptional violations is the employee's intention. With respect to decision-based errors, the employee is unaware that he or she misunderstood the rule or failed to apply it correctly. With exceptional violations, the employee understands the rule, but either does not trust the rule's effectiveness (or appropriateness) or thinks that the alter- nate response he or she conceived is more appropriate. When exceptional violations occur, the applicability of the rule that is broken should always be revisited in the context of the situation in which it was violated. The following example describes an exceptional violation: a public transit agency has a rule that forbids bus operators from letting off passengers between stops. Due to bad weather and a passenger's request, a bus operator let off an elderly passenger between stops. The passenger felt it was too icy to walk from the stop to her home. 3.4 Situational Violations These occur because an employee is conflicted regarding the balance between adherence to the rules (e.g., procedures designed to ensure safety) and meeting performance goals (e.g., on-