[katieHaylor (OP)]

Elizabeth says:

I was driving along the highway when it was raining and thundering overhead. I remember someone saying that a car is a safe place to be in a thunderstorm, as it acts as a Faraday cage and the lightning will go around it.

Is this true, or will the engine shut down which could cause a huge accident?

What do you think?

[alancalverd]

Absolutely true of older cars with  mechanical injectors or carburettors and simple ignition systems, but I would not be surprised if some of the more sophisticated electronics objected to the magnetic pulse of a direct strike. That said, modern engines are supposed to default to a "limp home" condition when all else fails. Inside a stationary metal car is certainly the safest place to be during a thunderstorm but the possibility of sudden engine failure is interesting, to say the least. That said, most airliners receive a direct strike a few times every year, with very few reported problems.

[evan_au]

Other risks for a moving car in a thunderstorm are: reduced visibility, increased stopping distance, likelihood of an uncontrolled skid, and being swept off the road if there is water over the road. In some parts of the world, tornadoes are also a risk.

But overall, lightning strikes very rarely on any given car, and today's electronic braking systems help a lot on wet roads.

Lightning is more likely to strike a tree or lamp pole beside the road than to have a direct strike on your car.
So, continue at a safe speed for the conditions, and turn on your headlights.
If you really can't see the traffic, pull well off the road and stop the car, but leave your lights on.

[chris]

Not so safe if you get washed away in a flash flood... http://www.abc.net.au/news/2017-10-02/bundaberg-hit-with-downpour,-flash-flooding/9007022

[chris]

some of the more sophisticated electronics objected to the magnetic pulse of a direct strike

Any idea how significant this would be; and how would one go about calculating or modelling it?

[evan_au]

Any idea how significant (EMP) would be; and how would one go about calculating or modelling it?

It really depends on how the electronics is designed.
- Almost nothing will withstand a direct lightning strike, injecting voltages over 30,000V and currents reaching perhaps 6,000A.
- But the car body acts as a partial Faraday cage for the electronics in the car
- If you connect electronic modules via optical fiber, that reduces the number of ways an electrical spike can get into the electronics
- If you install the electronics in an earthed enclosure, that reduces the intensity of pulses radiated into the circuitry
- If you put surge suppressor components on all electrical inputs and outputs, that will reduce the degree of problems
- If you thoroughly test the equipment with all types of electrical and magnetic pulses and continuous signals, in all axes, you are much more likely to withstand a nearby lightning bolt (eg to the car body).

I have designed hardened electronics, and even seemingly trivial differences in circuit layout can have dramatic impact on susceptibility to interference. On one occasion, the circuit that was intended to reset a microprocessor on power-up was acting as a loop antenna, picking up any external radio frequency interference, and injecting it straight into the reset pin of the microprocessor.

Military equipment is designed to withstand EMP, and there are well-developed techniques that assist with this - unfortunately, it often carries a significant cost penalty.

[Zer0]

When the Thunderstorm is close by or directly above you, a Lightning bolt would comprise of two distinct components.

Lightning Strike= Flash Bolt + Thunder Sound.

Just from the moment you see the Flash, Count the number of seconds until you hear thunder. If you have a digital or analog watch, begin timing as soon as you see the lightning and stop as soon as you hear the thunder. If you don’t have a watch, do your best to count the seconds accurately. Say "One one thousand, two one thousand..." in your mind as you count.

Calculate the distance from lightning in miles or kilometers. Sound travels one mile every five seconds and one kilometer every three seconds. Therefore, if you want to find out how far you are from lightning, divide the number of seconds by 5 if you want the answer in miles and divide it by 3 if you want the answer in kilometers. The delay between when you see lightning and when you hear thunder occurs because sound travels much more slowly than light.

 Here's what you do:
Let's say you counted 18 seconds. To find your distance from the lightning in miles, divide 18 by 5 to get 3.6 miles. To find your distance from the lightning in kilometers, divide 18 by 3 to get 6 kilometers.

Though you won't be able to get a completely accurate result because the weather may vary in temperature and humidity, which will slightly affect the speed of sound, this is a good way to estimate how far you are from the lightning.

Calculate the distance from lightning in feet or meters. Sound travels at a speed of about 344 meters, or 1,129 feet, per second. To calculate your distance from the lightning in meters, just round 344 down to 340 and multiply the number of seconds by 340. To calculate your distance from the lightning in feet, just round 1,129 up to 1130 and multiply the number of seconds by 1130.

 Here's how you do it:
Let's say you counted 3 seconds. Multiply that number by 340 to get your distance in meters. 3 x 340 = 1020 meters. Multiply that number by 1130 to get your distance in feet. 3 x 1130 = 3,390 feet.

This would Help you to self analyze the proximity or closeness or approximate location n distance between the Thunderstorm and You.

It is a widespread myth that the reason vehicles provide protection from lightning is due to the tires.

In actuality, lightning flows around the outside of a car, and the majority of the current flows from the car's metal cage into the ground below. In essence, a car acts like a mobile Faraday cage.

However, not all vehicles are created equal anymore.

Convertibles do not have metal roofs, which compromises the Faraday cage affect. In addition, some vehicles are manufactured out of non-metal parts, which impedes electricity's ability to flow through the car.

Another caveat with regards to lightning safety within vehicles is the fact that some portions of the current can flow through the vehicle's electrical systems and metal appendages including radios, cell phone chargers, GPS units as well as car door handles, foot pedals, the steering column and the steering wheel.

The National Lightning Safety Institute reports that some vehicles struck by lightning experience external damage, including pitting and arcing, as well as internal damage to electronic systems and components.

Another example of this happened in early June 2015, when a woman's car was struck on Interstate 4 near Polk City, Florida, frying the vehicle's electrical system.

The car's air bags deployed due to the sudden shutdown of the engine from the lightning strike, leaving the woman with a bruised rib cage.

If you can't find more substantial shelter in a sturdy building, a metal-topped vehicle can keep you safe in the event of a lightning strike.

If you are driving, pull to the side of the road, turn on your hazard lights, turn off the engine and wait out the storm.

Fold your hands in your lap and avoid touching anything metal within the car. You also should not to touch the radio or talk on a cell phone, especially if it is connected to your vehicle.

Once the electrical current has passed through the vehicle and entered into the ground, it is technically safe to exit the vehicle.

Simplest Explanation - Lightning Strikes location cannot be Predicted as yet, the lightning rods n safety equipments do not attract electrical lightning bolts but are just basic tools used to transfer electrical charge quickly n safely into the ground.
Any object at the highest location point from its surroundings can be a possible probable strike point, but still there's no guarantee of it.
You may think of good conductors or semiconductors or bad conductors but, lightning bolt could strike a metal pole, bark of a tree or saltwater in the sea or just plain ground as well.

Driving directly under a ThunderStorm could be risky considering poor visibility n slippery road conditions, you might have perfect 20/20 optical vision good quick reflexes n a great branded abs airbagged hybrid car but what about the spectacled granny driving an old convertible infront of you? Or maybe an exhausted n tired drooling truckdriver gassing his 18wheelered behind of you?

Pulling over at a safe distance from the road n switching off your engine does not guarantee lightning won't strike you. Considering the probability of a lightning striking you directly versus it would strike something or someone else you do have very good chances of not being struck, try staying indoors would increase your chances incredibly.
Once you are directly struck, chances of survival are very low, immediate cardiac arrest, dilated pupils, extensive body burns, ear curtains damaged n even temporary damage to the nervous system.

P.S. - (while indoors try n avoid long duration landline calls n suppress those hot shower desires for a while) 👼

*All Data Collected n Combined from respective Sources :

https://m.wikihow.com/Calculate-the-Distance-from-Lightning

https://weather.com/storms/tornado/news/what-happens-when-lightning-hits-car-20140625

Basic Conceptual Understanding - Wikipedia & Quora. 🙏

[Bill S]

Some good, sound advice here, but it is worth remembering that on the road in a storm, especially in heavy traffic, your chances of being hit  by lightning are vanishingly small compared with the chances of being hit by, or hitting, another vehicle.  My reaction would always be guided by the road safety aspect.

[mikerhaord]

Thunderstorms have never stopped me from driving a care

[petelamana]

I have always been led to believe that the grounding properties of a car's rubber composite tires "protect" the occupants.

[wolfekeeper]

No, the rubber makes no significant difference- if you think about it the lightning has jumped kilometres down from the sky a few inches of rubber aren't going to do much!

Incidentally, although the car is highly protective, and the metalwork attracts the lightning and will nearly always save you in a direct strike, I believe there have been cases where the lightning has gone in through a window and still struck somebody. A perfect shield would need much smaller holes. Winding up windows is certainly advisable, since glass is an insulator, but probably even that isn't a total guarantee.

[Colin2B]

Winding up windows is certainly advisable, since glass is an insulator, but probably even that isn't a total guarantee.

Good advice. Lightening jumping across the gap of a partially open window and the mouth of a cave have produced enough heat to cause serious burns.

[alancalverd]

No, the rubber makes no significant difference- if you think about it the lightning has jumped kilometres down from the sky a few inches of rubber aren't going to do much!

Fact is that tyres are made from carbon-loaded conductive rubber to ensure that the vehicle is a grounded Faraday cage. Less from the point of lightning protection than to prevent sparking during refuelling.

[diverjohn]

I recall seeing a photograph from the 1950s published by a car manufacturer, Ford as I recall, that showed some poor engineer sitting inside a sedan that was being struck by the equivalent of a lightning bolt. It was clear in the photograph that the driver was safe from harm and I could see the electric charge forming a line across the rubber tire on the front wheel from the steel rim to the surface of the road. I think that when the rubber tyre is wet it will be able to conduct electricity across its surface to some degree, especially if there is salt on the road that splashes onto the wheels.

[RD]

some of the more sophisticated electronics objected to the magnetic pulse of a direct strike

Any idea how significant this would be; and how would one go about calculating or modelling it?

Apparently the electronics survive, see ....

https://youtu.be/GZxgYNnkBd0?t=3m42s

[MartyParty]

Yes as far as i know it is safe to be in a car during the thunderstorm, since it works like a Faraday cage. Now what is a faraday cage? Well sometimes physicists go into a metal cage, without a metal floor they stay inside and someone conducts high voltage and current electricity(It is not the high voltage that kills, it is the current). and the physicist inside the cage is completely safe, the electricity doesn't kill him/her. He/She is completely safe.Why?
Because metals conduct electricity, some more than other and so on, it depends on where they are in the Periodic table. In it the more an element is on the left, the stronger it's metal character is, the more it is on the right the stronger it's non metal character is. So, let's assume the car is made out of iron only on the outside, and some non-conductor of electricity on the inside, say plastic, so your car is made out of iron on the outside and plastic on the inside, in such a way that you do not have a touching point(some place where you touch the Iron) with the Iron and a lightning strikes exactly at your car, the electricty would hit the iron and it will cover the whole "surface" of your car on the outside, and you would be completely safe, from the high voltage and the high current the lightning brings. Your car is a faraday cage on it's own