Remote car key

It's funny to hear people complaining about usability of toys they use. This one is from a friend of mine who just bought a new car a few months ago. The key of a car has two remote buttons:

  • one for unlocking a car and
  • one for locking a car.

But there are 3 functions associated with these 2 buttons:

  • when pressing the unlock button the car opens (which is to be expected)
  • when pressing the lock button ONCE the car locks (which is to be expected)
  • when pressing the lock button TWICE the car locks and it disables the inner door latches so the car can not be opened from the inside - to prevent someone opening the door from the inside after breaking the window (as it is explained in the manual)

Now the user has two choices: locking the car in a half safe mode (the second option from the list) and locking the car in the full safe mode (the third option from the list) :). The question is why would someone lock the car without this safety feature (pressing the button only once)? My friend is now complaining that he always has to press the button twice to lock the car and he never presses it once because he doesn't want to leave the car in a half safe mode.

There is another question to this. Who would like to stay locked in a car and not being able to open it from the inside. Imagine if pressing this button once would lock the door from the inside as well (as my friend would like it to have). Imagine pressing it by accident and being involved in a car crash and not being able to exit. So there's a user's safety issue involved. But the same the button could be accidentally pressed twice while being in the car (the possibility for this is small but it still exists) and the driver is in danger again.

This situation has two modes (with the car being locked):

  • while in a car I would like to be able to open the doors from the inside (some cars lock the door automatically when the car starts so no one can for example open the door while a driver is waiting for a green light at the intersection)
  • while not in a car I would like not to be able to open the doors from the inside (if that is considered more safe by the automobile industry)

There is another mode in which car is not locked:

  • while in a car I would like my doors to be unlocked (some people don't like being locked in a car for various reasons)

The solution could very simple (with sensors for example). First thing to do is to offload the burden from a user:

  • if someone is in a car disable locking the doors from the inside if the lock button is pressed (X times)
  • if there's no one in the car lock it from both sides if the lock button is pressed

Now the user has the same two buttons and the same three functions but locking the car works differently without user knowing it - so concerning the user there are two functions only. Putting it differently there are still two locking modes but the user doesn't need to know it because it is not affecting her/him directly. User only presses the lock button once.

Edit 22/6/2010: It just crossed my mind; doors could be automatically unlocked in a car accident so someone could open it from the outside to help. It could be done automatically when the airbag fires up for example.



Interfaces that have 3 buttons and 27 features are always considered bad (Donald Norman, The design of everyday things).

How to know if the toilet is occupied

This one is sketchy. In the office we have several toilets with nice doors. There is no handle on the outside so it is obvious that the door needs to be pushed if someone needs to get in (there is a pulling handle on the inside). But what if the toilet (or restroom if you wish) is occupied. I often find myself pushing the door and wondering why the door does not open for a second or two. Then I realize that it is occupied and I have to wait. And when I'm on the other side of the door people push it to get in before realizing that it is occupied.

Looking more closely there is a difference between the locked and unlocked door. When the door is unlocked, the line on the locker is horizontal and when the door is locked the line is vertical. I'm not sure if this sign was put there intentionally or it just happened by accident. I'm voting for the later. And I'm hoping that whoever did this lock will further develop it and add some standard colour convention: E.g.: green circle when the toilet is not occupied and red one when it is. An even more advanced interface would be putting this coloured circle in the eye level because right now it's in belt level.


Road signs that don't help (whoever)

This one made me laugh! There's something wrong with the design of these signs. Simply because they don't do their jobs :).

On one of our many walks outside (we have to make kids tired to have a better sleep at night :)) we came across this situation. There was an area of the on street parking space (or parking bays) that was protected by traffic cones and workers put two signs at each side with a notice "NO PARKING BETWEEN SIGNS". Two hours later the cones were put on the sidewalk and tree cars were parked between the signs. It is interesting how people just ignored them. There was a free parking space few meters down the road but why walking that much. It reminded me of Slovenia and a joke I have about Slovenian drivers who try to park as closely to their destination as possible: "they would go to the toilet with a car if possible". Maybe sometimes in the future. In the mean while ... get on your feet and do some walking people :)!



PS: I take advantage of this behavior as well. In the town where I work there is a lack of parking places and a huge parking space by the town. While everyone tries to find a parking spot that is nearer to the town (and even circle around searching for one), 100 meters away there is no jam. So I pass by walking while those people still circle around. Amazing, how some people are willing to sacrifice 15 minutes or more of their life every day just for not walking 100 meters :).

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Fuel filler neck and the pump nozzle

Pump nozzles are in use every day by millions of people worldwide and so many of us sometimes make a mistake of putting gasoline in a diesel car or diesel in a gasoline car. We were on a walk the other day and saw a line of cars from a local company that had a sticker on each filler flap describing the type of fuel that goes into the tank. Probably it was a maintenance guy who put them on after rescuing his coworkers a few times when they mistakenly filled the tank with the wrong type of fuel. 

It reminded me of my own experience. It was 9PM, December, cold and very dark outside. That week I was driving my mum's car which uses gasoline and I filled up her tank a few days before. But that day my wife gave me a lift and she came to pick me up. It was after 12 hours at work and we stopped at the grocery store on a way home adding an extra hour on top of 12. After the store we stopped at the gas station as we were running out of fuel. I didn't even think about which nozzle I grabbed and put in a filler neck but I realized it was not the right one when I pulled it out. I filled the tank of our diesel car with a gasoline.

It cost me 100€ and at the end I had 50 liters of gasoline in 5 10l containers. I know it is not life threatening if a gasoline is put in a diesel car. I know that the engine can't break if it happens. But it's annoying. I had to park a car, call someone to pick us up, waited there for half an hour in the cold and came home one hour later without a car. I had to borrow the car the next day, go to a garage, wait for them to empty the tank, pay for it, get my wife from work, drive her to the garage so we could drive home both cars. It took me the whole working day to get it sorted.

There is at least the convention of green nozzle for gasoline and a black nozzle for diesel (in Europe at least, because in USA green nozzles are used for diesel). But is it enough? Some can argue that it works with traffic lights (red for stop and green for go) but some people drive trough red light not even noticing their mistake (I was with a friend once in a car when she did it). No wonder then, that people mistakenly fill the gasoline in diesel cars if there is no danger associated with it.

But while there's nothing much to be done on streets (forget cameras and fines), making mistakes on gas station could be simply prevented. For example: round nozzle for gasoline, square for diesel, triangular for natural gas ... each of different colour. Filler necks should be of  the shape to accept only appropriate nozzle. That simple.

Edit: I just remembered a series of ads from Slovenian Ministry of internal affairs inviting drivers to drive carefully, within speed limits, fastening seat belts, etc. A part of every ad were these smiling faces that resemble my shaped nozzles :). But without colours ...


Taps 3

It is fair to show a good design of a tap control - actually a shower control. I came across this one in a hotel in the Lake District (UK). It has two handles:

  • the top one for the temperature and
  • the bottom one for the water pressure

It has labels ON/OFF on the top and COLD/HOT under the bottom handle. The labels are in gray over the shiny silver and not visible enough. It would be nice to have some universal labels (like red/blue for temperature and something like increasing number of drops from 0 to 5 for pressure) for non English speakers (since it is used in a hotel), but other than that it is a nice shower control.