World Usability Day and the Montreal metro

Next Thursday (Nov, 13) is World Usability Day. From the description:

World Usability Day was founded in 2005 as an initiative of the Usability Professionals’ Association to ensure that services and products important to human life are easier to access and simpler to use.

This year’s theme is “Transportation”, treating various aspects of usability such as interaction, signage or security. There are numerous local events across the globe picking up this theme to one degree or another. As there is no event here in Montreal, I dediced to contribute a little snapshot I took in the metro (subway) the other day. It shows the train’s emergency brake:

Montreal Metro emergency brake

Before you read on, think about what would be the interaction you would take to activate the brake in case of an emergency.

For me it is not obvious. So far, I have come up with three possible interactions that I think people might want to try:

Montreal Metro emergency brake 1

People might want to pull the brake out of the mount, away from the metal plate.

Montreal Metro emergency brake 2

People might want to pull the brake up in a circular motion, like opening a hatch or a hinged lid.

Montreal Metro emergency brake 3

And people might want to pull the brake down. This one might be the most common way to operate emergency brakes but to me, the short slot of about 1cm in the metal plate doesn’t suggest that the entire train would stop when pulling the brake for such a short distance.

Overall, the brake’s presentation lacks affordance, or in other words, it lacks a design that allows even first time users to immediately operate the brake in the correct manner. Why is affordance so important in this case? Emergency brakes have to respond very quickly to stop the train. In addition, I think you can assume that of all the subway passengers, practically no one has ever operated an emergency brake before, therefore making everyone a first time user. If people in an emergency now start trying different means of operating the brake, precious time is lost.

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3 thoughts on “World Usability Day and the Montreal metro

  1. Pingback: Montreal Metro – Usability part 2 « Advancing Usability

  2. If you are too slow to try 3 mouvements of a lever in less than 3 secs, you should not use the Metro. Beside, you can see the groove going down.

  3. A valid point, however you need to take into account that the groove is not well visible from straight front as well as the train’s speed.

    According to Wikipedia, the average speed of Montreal Metro trains is 40 km/h which equals about 11 m/s. Allowing two extra seconds for someone to figure out the emergency brake means 22 meters of extra train movement. Quite a lot I would say. At top speed (72 km/h) this means an extra of 40 meters.

    There is a somewhat comparable situation in Germany at the moment, where Siemens had to delay a €500MM high-speed train delivery because of a one second delay in the emergency brake system: http://tinyurl.com/d7gn2rb (Link to automatic translation of a news article)

    So while it may seem pedantic, I don’t think safety-related mechanisms should leave room for ambiguity.

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