Absolutely amazing nobody was killed. I wonder what the conversation was like on the bus keeping folks in while there was fire encroaching. Even if you don't touch the conductors, potential gradient can ruin your day.
In this situation it means that the ground (or water) near a downed power line is charged, but the voltage drops quickly as you get further from the conductor (that's the potential gradient).
It can ruin your day if you walk towards or away from it, because your feet might bridge two areas of ground that have a 10kV difference.
Your body being a bag of salty water makes a much better conductor than dirt, so the voltage takes the path of least resistance.
The safest advise is don't try to traverse the ground in that situation at all. However, if you must, the advice is to hop with your feet together or shuffle with very small steps (with the understanding that if you fall you're almost certainly going to fry).
Minor quibble: This implies that electricity only takes the path of least resistance. Electricity actually takes all available paths in inverse proportion to the impedance of the paths. This is why grounding rods don't keep you from being electrocuted. I'm looking at you, sketchy lamp-post.
Good clarification. When I was a kid I found out that standing on the edge of the kitchen sink and touching the pull chain on the lamp in the soffit overhead would 'tickle'. I was so proud when I told mom and dad! :P
Bad idea. If you slip even once, suddenly you don't have "just" the 1m of an ordinary step but 1.5 or 2m... and the longer, the greater the voltage gradient.
In theory if you leap from the bus such that you are completely in the air for a moment, you won't be in contact with a conductor and the ground at the same time. (Given enough voltage, electricity can cross the gap to the ground, but if there's a fire you gotta do what you gotta do.) You then have to keep hopping with your feet together or shuffle-step away due the the potential energy difference in the ground.
A problem is that many people who use a bus are not physically capable of a leap. They may be elderly, disabled, pregnant or simply be very small children.
I'm pretty sure that even almost invisible smoke can already cause significant trouble in this respect. Partly because particles of smoke themselves can be electrostatically attracted to objects under significant voltage, so even low density smoke can concentrate itself in problematic places. See Figure 3. and the text above it in https://www.osti.gov/servlets/purl/3313 .
We learned as kids stay put unless absolutely having to leave the vehicle. If you had to leave because of say a fire you were to keep both feet together and literally hop away like you say not walk. This is going way back it seems to make sense but I haven’t checked the source on this.
Shuffling is recommended over hopping because you're less likely to fall over. Shuffle in small movements keeping your feet on the ground and close together.
Where did you learn this? Were they specifically teaching you want to do if a power line lands on your car? That seems like a pretty rare situation. Or was it about electric cars or busses?
Is power line landing on things all that rare? There's lots of power lines on poles in cities around the world. Also very strong winds like to down trees, which then sometimes down such powerlines.
I am from denmark, we have practically no power lines above ground except for the occational high voltage lines which they are also planning to bury. By 2040 it will only be allowed to have 400KV lines above ground.
I’m grade school. I am in Canada and almost all our power lines are above ground. Yes it was specific to if a power line landed on your car or even if it crashed beside your car and you had to get out.
