Content Principle

1 ndicators/Measures

Score

Comments

Potential Refinements

Tasks are allocated appropriately between and among humans and technology

• * Users are provided with appropriate tasks, that is, not monotonous tasks that can be performed by technology with human supervision, but those that provide appropriate challenge.
• * Users are given tasks where there is unpredictability such that judgement and interpretation are needed.

2

• * Users retain the task of choosing when to stop, but are given additional warnings.
• * Users are slowed in stages to give the feeling of preparing to stop.
• * Train drivers are given a healthy-state light to monitor. However, there is little they can do immediately to assist the situation if the warnings have ceased to work beyond using the train horn to alert road users and reporting the issue.

• * The red fight should activate at the point where there would be a collision if the user chooses to cross. This ensures the credibility of the warning (e.g. it is not activated for 200 m prior to the RLX if the train is travelling at 20 km/h).
• * Road users should be given a failure mode display for the sign.
• * Road users should be educated about the meaning of the sign and the flashing light on the train.

Useful, meaningful and whole tasks are designed

• * Users are given whole tasks, rather than fragmented pieces of tasks to perform.
• * Users perceive the tasks they are performing to be meaningful or useful.

1

• * Users would understand the significance of the task, but there is nothing added to give the task meaningful ness.
• * Speed reductions and rumble strips after the RLX will be perceived as unnecessary.

* Speed reductions and rumble strips should be present only on approach - the limit should lift to 80 km/h, then 100 km/h shortly after the RLX.

Boundary locations are appropriate

• * Boundaries or divisions between users or user groups are based on whole processes.
• * Boundaries do not impede sharing of knowledge and experience.

1.5

• * The design introduces a new form of communication between the train and the road user via the light on the train. This helps to communicate across boundaries.
• * Nothing included in the design to share knowledge and experience.
• * User groups not considered include rail maintainers who operate track vehicles.

* May need to install red fights on non-train vehicles that use the railway (e.g. track machines). Will there be means for them to engage a test switch to start the warnings if not detected by the train detection loop?

Content Principle

1 ndicators/Measures

Score

Comments

Potential Refinements

Boundaries are managed

• * The design facilitates supervisors, users or user groups to manage the boundaries or interfaces with other users or groups.
• * Boundary management incorporates buffering from external disturbances or changes in the wider environment.
• * The design empowers users to define the rules and processes that constrain their activities.

1

• * No boundary management is present. Instead, the design relies on road rules being followed.
• * The flashing light sign would be advisory rather than regulatory - meaning that people can to some extent choose to ignore it in certain circumstances.
• * Users are unable to define rules and processes.

* Potential to introduce a feedback system online so users can give feedback about the timing of sign and train light activation.

Problems are at their source

* The design facilitates the detection of and recovery from problems (including negative behaviours)

at the time and place at which they occur.

* The design provides people with the competency and authority to control problems.

1.5

• * Train drivers are given a healthy-state light to monitor. However, there is little they can do immediately to assist the situation if the warnings have ceased to work beyond using the train horn to alert road users and reporting the issue.
• * Road users are not given a failure mode display for the low-cost signs.
• * The graduated speed reduction means users will have opportunity to see another sign if one is missed (currently just one sign for 80 km/h limit is present).

• * Provide a failure mode for the sign (e.g. a sign displaying ‘no warnings provided - look for trains’).
• * Could use portable speed feedback signs on approach to the RLX.

Risk

Addressed by Design Concept?

Road users not aware of upcoming rail level crossing

Yes - through rumble strips, enhancement of road markings, speed signs on approach and rail level crossing warning signs

Road users not aware of rail level crossing warnings

Yes - through the addition of advance warning signs and warning signs at the rail level crossing with flashing lights

Road users not aware of an approaching train

Yes - through the addition of a red light at the front of the train to draw attention, as well as the addition of advance warning signs and warning signs at the rail level crossing with flashing lights

Road user not checking for trains sufficiently

Yes - the speed reductions are intended to provide road users with more time to check for trains. Additionally, the red light on the train is intended to attract attention to an oncoming train

Road user not detecting a second or subsequent train

The design does not specifically address this risk

Road user misjudging the speed or distance of the train

Yes - the red light on the front of the train is intended to draw attention to the train and assist road users to make decisions about its speed and distance from the rail level crossing

Road user choosing to cross when warnings are activated/a train is approaching

The design does not specifically address this risk

Road user queuing or short stacking on the crossing

The design does not specifically address this risk

Warning systems failing to announce the presence of a train

This risk may be increased in this design, as a low-cost warning device is proposed