Yesterday the OMB’s Office of Information and Regulatory Affairs
announced
that it had approved an information collection request (ICR) from the DOT’s
Federal Railroad Administration for an Experimental Investigation of
Automation-induced Human Error in the Locomotive Cab. The study will be
conducted by the DOT’s Volpe Center using
their Cab
Technology Integration Laboratory (CTIL).
The Study
The study will look at two different types of train
automation systems currently in use by railroads in the United states; the Trip
Optimizer and Electronic Train Management System (ETMS) Positive Train Control
(PTC). According to the final Supporting
Statement [.DOXC download] provided to OIRA, the study will assess three
working hypotheses:
• Automation provides specific
performance benefits (e.g., TO reduces fuel usage; PTC prevents overspeeding
and transgressions into workzones or past a red signal) compared with manual
control;
• Automation does not reduce perceived workload in the locomotive cab
compared with manual control; and
• Automation condition will show more errors in high workload situations
than in low workload situations (e.g., distractions lead to failure to notice
mode transitions) and the manual condition will not.
That Supporting
Document provides a fairly detailed description of the proposed test. The idea
behind this study is that disruptions to the engineer/conductor attention at
critical junctures in train operation lead to errors. The specific disruption
that will be studied will be a radio call from the dispatcher carefully timed
to changes in operation of the automation system. The Supporting Document notes
that an earlier study suggested that this might be a specific cause of operator
error in using train automation systems.
The results of the
study will be published as an FRA technical report at some future date.
Commentary
This looks like it will be an interesting study and it may
have important implications for a number of other areas where automated safety
critical systems require operator interactions.
The three hypotheses being tested here are an interesting look
at automation systems in their own right. The first goes to the efficacy of the
safety-critical automation system; if that assumption is not true, then the
entire design of the system is called into question. The second hypothesis is a
human factors issue, but it also is an important question of safety design. If
the safety critical system requires operator action, it should not add to the operator’s
workload else it increases the probability of a safety-critical human-error;
that is the third hypothesis in a nutshell.
The FRA is fortunate that it has simulator capacity to
evaluate these concerns. Designers of a process safety system at a chemical
plant (for instance) are unlikely to have that capability.
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