Downed power lines on your car and step potential¶

When a live utility wire drops onto your car or touches the ground nearby, the metal shell of your vehicle and the surrounding pavement become charged with lethal voltage. Stepping out of the car normally creates a direct path for electricity to travel through your body into the earth, causing instant electrocution.

This guide explains why staying inside your car keeps you alive, how to warn bystanders away from energized ground, and the exact jump-and-shuffle method to use if a vehicle fire forces you to evacuate.

Do this now¶

1. Stay inside your vehicle. Keep your seatbelt on or stay seated, keep your hands in your lap, and do not touch any interior metal door frames, window cranks, or pillars.
2. Never step out of the car normally. Touching the metal body of the car and the ground at the same time completes an electrical circuit through your body and is immediately fatal.
3. Call your local emergency number. Dial 911 in the United States and Canada, 112 across the European Union, or 999 in the United Kingdom (see all emergency numbers) and report specifically that a live downed power line is on or near your vehicle so the electric utility can de-energize the grid.
4. Warn bystanders to stay back. Sound your horn or shout through a slightly cracked window to tell anyone approaching to stay at least 10 meters (33 feet) away from the car and the wire, and up to 30 meters (100 feet) away if the line is a high-voltage transmission wire.
5. Wait for utility workers to confirm the line is dead. Do not attempt to exit the car until electric utility personnel or firefighters explicitly tell you the line has been grounded and de-energized.
6. Jump clear only if the car catches fire. If smoke or flames force you out, open the door without touching outer metal, cross your arms over your chest, jump clear with both feet together so you never touch the car and the ground at once, and shuffle away with both feet pressed together for at least 15 meters (50 feet).

Emergency decision flow for downed power lines¶

flowchart TD
    Start["Downed Power Line on or Near Vehicle"] --> FireCheck{"Is the vehicle on fire or filling with smoke?"}
    FireCheck -->|No| StayIn["Stay Inside the Vehicle<br/>Do not touch metal door frames<br/>Keep windows closed or slightly cracked"]
    StayIn --> Call911["Call Emergency Dispatch<br/>911 US and Canada, 112 EU, 999 UK<br/>Request immediate utility line shutoff"]
    Call911 --> Warn["Warn Bystanders Away<br/>Honk horn and wave people back<br/>Minimum 10 meters (33 feet) clearance"]
    Warn --> Wait["Wait for Utility Confirmation<br/>Exit only after crew grounds the line"]

    FireCheck -->|Yes| OpenDoor["Emergency Fire Evacuation Only<br/>Push door open using plastic handle<br/>Never touch exterior metal"]
    OpenDoor --> Jump["Jump Clear with Both Feet Together<br/>Cross arms tightly over chest<br/>Never touch car and ground at once"]
    Jump --> Land["Land on Both Feet Simultaneously<br/>Keep knees slightly bent for balance<br/>Do not fall backward onto the car"]
    Land --> Shuffle["Shuffle or Hop Away<br/>Slide feet without lifting them<br/>Move at least 15 meters (50 feet) away"]

Why the inside of your car protects you¶

When an energized power line rests on a motor vehicle, the metal body of the car acts as an electrical enclosure similar to a Faraday cage. Electricity flows across the outer conductive steel or aluminum skin of the vehicle seeking a path into the earth. As long as you remain entirely inside the passenger cabin and do not create a bridge to the ground, your body remains at the same electrical potential as the cabin around you, and no current passes through your tissues.

A common myth states that rubber car tires insulate a vehicle and make it safe. In reality, high-voltage utility lines carry thousands of volts that easily overcome the insulating properties of standard tires, which also contain conductive carbon black and steel belts. High voltage frequently arcs right through the tires or burns them until the metal wheel rims rest directly on the conductive pavement.

The inside of your car is safe not because of the rubber tires, but because there is no voltage difference across your body while you sit inside the cabin. That protection disappears the instant any part of your body or clothing touches the ground while another part touches the vehicle.

Understanding voltage gradients and step potential¶

When a live wire touches the earth or energizes a vehicle resting on the road, electrical current radiates outward into the soil or pavement from the point of contact. Because earth, asphalt, and concrete offer resistance to electrical flow, the voltage drops gradually as the distance from the wire increases. This creates concentric rings of decreasing voltage around the wire and car, much like ripples radiating outward when a stone drops into water.

flowchart TD
    Wire["Point of Contact: 13,800 Volts"] --> Ring1["Ring 1 at 1 Meter (3 Feet): 9,000 Volts"]
    Ring1 --> Ring2["Ring 2 at 2 Meters (6 Feet): 6,000 Volts"]
    Ring2 --> Ring3["Ring 3 at 4 Meters (13 Feet): 3,000 Volts"]
    Ring3 --> SafeZone["Safe Distance Beyond 10 to 15 Meters (33 to 50 Feet)"]

Touch potential¶

Touch potential occurs when you stand on the ground and touch an energized object, such as the door frame of your car. While your hand touches the car body at full line voltage (for example, 13,800 volts), your feet stand on ground about 1 meter (3 feet) away that may be at 9,000 volts. The resulting 4,800-volt difference drives a massive current straight through your arm, heart, and legs into the earth.

Step potential¶

Step potential occurs even after you are completely clear of the vehicle. If you take a normal walking stride of 0.8 meters (2.5 feet) away from the downed wire, your back foot remains in a higher-voltage ring while your front foot steps into a lower-voltage ring. Because human tissue conducts electricity far better than dry soil or asphalt, the electrical current takes a shortcut up one leg, through your pelvic cavity and torso, and down the other leg. This causes instant muscular paralysis, causing you to fall flat on the ground across an even wider span of voltage rings.

How to jump clear and shuffle away if the car catches fire¶

High-voltage current passing through a vehicle frame and tires often ignites the rubber tires, brake fluid, or fuel lines. You must only evacuate a vehicle under a downed power line if an active fire, heavy cabin smoke, or a leaking fuel hazard poses an immediate threat to your life.

Follow this exact sequence to escape without creating touch potential or step potential:

1. Prepare the door carefully. Unbuckle your seatbelt and push the door all the way open using the interior plastic handle. Do not touch the painted metal exterior, window frame, or door edge.
2. Stand on the interior threshold. Stand up on the dry rubber floor mat or plastic door sill inside the cabin. Look down and pick a flat, clear landing spot on the pavement free of loose wires.
3. Cross your arms over your chest. Tuck your hands tightly against your shoulders or lock your elbows to your ribs so your arms cannot flail backward and brush the door frame as you leap.
4. Jump with both feet together. Spring outward away from the car so that your body is completely airborne before your feet touch the ground. At no point may one foot remain on the car while the other touches the pavement.
5. Land on both feet at the same time. Absorb the landing with slightly bent knees while keeping your ankles and feet pressed firmly together. If you feel yourself losing balance, fall forward away from the car, never backward against the vehicle body.
6. Shuffle or hop away for at least 15 meters (50 feet). Keep both feet pressed side by side and slide them across the ground in tiny inches without ever lifting a foot, or hop like a rabbit with both feet locked together. Never take a normal stride until you are at least 15 meters (50 feet) past the vehicle and any visible wire ends.

Power line types and safe clearance distances¶

Different power lines carry vastly different voltages, and wet pavement or metal fences can conduct current far beyond the visible wire. Use this comparison table to determine minimum safety perimeters.

Hidden hazards around downed utility wires¶

Even if a downed power line is not directly touching your car, the surrounding crash scene contains hidden electrical traps that kill well-meaning bystanders and motorists every year.

• Automatic circuit reclosers: Utility grids use automated switches called reclosers to test whether a line fault (such as a falling tree branch) has cleared itself. A downed wire that lies completely silent and dark on the road can suddenly surge back to full lethal voltage seconds or minutes later as the substation automatically attempts to restore power up to three or four times.
• Energized guardrails and fences: If a downed line falls across a steel highway guardrail, a wire farm fence, or metal road signage, that metal structure can conduct lethal voltage for hundreds of meters (yards) in both directions. Never climb over or lean against a guardrail near a crash involving utility poles.
• Wet pavement and storm runoff: Water reduces the electrical resistance of the road surface and carries current down gutters, ditches, and puddles. Never step into standing water anywhere near a damaged utility pole.
• Tree branches touching lines: Green wood contains water and sap that conduct high-voltage electricity. If a broken tree limb is resting across both a power line and the hood of your car, treat the tree branch and your vehicle as fully energized.

What to do if you witness someone else trapped or shocked¶

If you arrive at a crash scene where utility poles are damaged or cables are hanging low, your primary responsibility is keeping yourself and others out of the energized zone.

• Stop your vehicle at least 15 meters (50 feet) back before reaching any sagging or fallen overhead cables, and inspect the roadway for dark wires that blend into asphalt at night.
• Stay away from metal barriers including steel roadside guardrails, chain-link fences, and metal light poles that could be in contact with the wire further down the road.
• Instruct trapped occupants to stay put by shouting from a safe distance or using a bullhorn, telling them to remain seated with their windows up until the utility company arrives.
• Do not touch an electrocuted victim if they are lying near the car or touching the wire, as their body remains part of the live circuit until the utility grid is shut off.
• Begin CPR only in a safe zone once utility workers have grounded the lines and fire crews have moved an unresponsive victim to a confirmed de-energized area.

Taking a hands-on first aid and CPR course from the Red Cross, St John Ambulance, or a local emergency training provider gives you the practical skills to resuscitate electric shock victims safely once the scene is clear of voltage.

Frequently asked questions¶

Can I drive my car away to break free from a downed power line?¶

No, you should not try to drive away unless there is an immediate life-threatening emergency and the wire is clearly not tangled around your axles, wheels, or bumpers. Driving with a live wire snagged on your vehicle can pull down an entire row of utility poles, snap high-tension cables that whip across the windshield, or rupture fuel lines while high-voltage arcs ignite the leaking gasoline.

Why do downed power lines stop sparking even when they are still live?¶

A downed wire often sparks violently when it first hits the pavement, then goes completely quiet and still while remaining energized at thousands of volts. Utility substations also use automated circuit reclosers that temporarily pause current for a few seconds and then automatically send high-voltage surges back down the line to test if the obstruction has cleared.

Is it better to shuffle or hop with both feet together?¶

Shuffling by pressing your feet tightly together and sliding your soles a few centimeters at a time without lifting them is generally safer than hopping. When you hop with both feet together on uneven pavement or gravel, it is very easy to trip and fall flat on your hands and chest, which spans multiple voltage rings and causes fatal electrocution across your heart.

Are electric vehicles safer or more dangerous when hit by a downed power line?¶

An electric vehicle (EV) still acts as a protective metal Faraday cage against an overhead utility wire as long as you remain inside the cabin, just like a gasoline car. However, high-voltage grid current passing through the chassis can damage the vehicle's internal 400-volt to 800-volt lithium-ion traction battery and trigger thermal runaway, making it critical to watch closely for white vapor, hissing noises, or smoke beneath the floorboard.

Related guides¶

• What to do after a car crash
• Electric shock first aid
• Power outage at home
• Regional grid collapse and blackout
• Emergency numbers directory