Wednesday, April 15, 2009

Should I cross the road now ?

Last week, I was lucky to have captured this image live.

This is about a traffic signal: Not the movie, this is about the signalling device used to control traffic. On one of the main roads near my residence, the traffic signal displayed one of the rare-to-be-seen visuals.

As seen in the image, this seems to be a signal to guide the pedestrian.

I would expect only one image to be displayed at this traffic signal.

Either the

'Red Pedestrian' meaning: Do not Cross now
'Green Pedestrian' meaning: It is safe to cross now
should have been displayed.
I was waiting at the other end of the traffic light and waiting for it to turn 'Green'.

And I was surprised at what I saw for the next 128 seconds.
Both the 'Red Pedestrian' and the 'Green Pedestrian' images were displayed simultaneously next to each other.

Then it turned to 'Green' image for few seconds and alternated between the 'Green' and 'Red' image after a set time interval.
I was not able to observe that 'two images at once' visual. :( [Not reproducible ?]
After a week long observation, I could not see this visual again.
Even after observing the signal continuously for 11 hours (10am - 9pm), the same scenario was not displayed.

My question to all the readers and their friends: How costly is it to miss this bug?

First of all, do you agree that it(display of two images simulataneously) is a bug?
Was this Race Condition not covered during testing?
Was this risk too costly to be avoided in the first place?
Was this risk covered and yet not fixed?

Few questions...


Ravichandra K.N said...

Hey, its bug whatever u observed. why it occured have to query the chip manufacturer only[:)].
In India signals rarely works, if it works also it won't work properly. Better don't think too much on to it.

Pedestrians(Specially bangaloreans) also don't care for the signals to turn green. they cross road at their will.[:)].

Brian Osman said...

Interesting observation. Sometimes our expectations don't match what we are expecting and often this bugs us. Seeing both signals illuminated and for an extended period is definintely out of the ordinary and this can bug us. IS it a bug yes.

As for the other questions, well that would depend on the manufacturer - possibly they didn't *find* it or they found it and *accepted* the risk. Either way its still a bug.

What else was happening at the time? Was there work conducted on the junction box? Was it raining? Was it humid? How are the lights controlled and was this opened to *contamination* (e.g. a human opened the box, fiddled with the controls, closed the box)? What was the outcome of the light display both green and red signals?

Thanks for your post!

Shafayet_qa said...


It may happen due to some changes after the release or some of the malfunctioning of hardware system. But the main problem is the seance of importance. If people thinks the traffic signal is important then this type of BUG will go away instantly other wise nobody cares. This is also true for any other product. If Client don't mind then y do the changes??? ..In this case "PUBLIC" is the client:(.

MaikNog said...
This comment has been removed by the author.
MaikNog said...

i agree with Shafayet_qa on this.
If this bothers you, it is a bug (for you).

Questions would be: Is there a function (which we are not aware of) which has the red/green at the same time? Maybe an internal maintenance/developer code function?

In a situation where it could be life threatening i also see the "Usability" reduced.

Would be interesting to know, if traffic signal for the car drivers also showed a similar or same red/green situation..

My stepdaughter in Pune reported the same occurance (red/green same time) to my wife last week... coincidence? Same manufacturer?