Roadside
What to Keep in Your Car for a Breakdown
A realistic kit that fits in one trunk bin, costs under $200, and covers the failures that actually strand people.
Quick answer
The core kit
Buy these first. Each one addresses a failure that genuinely strands ordinary drivers, and together they fit in a single bin.
| Item | Typical cost | What it solves |
|---|---|---|
| Lithium jump pack, 1,000A or more | $70–$120 | Dead battery with no second car available |
| Tire plug kit | $15–$30 | Nail or screw punctures in the tread |
| 12V tire inflator | $30–$60 | Slow leaks, low pressure, reseating after a plug |
| Reflective triangles or LED flares | $20–$40 | Being seen on a shoulder, day or night |
| LED flashlight or headlamp | $15–$30 | Everything above, after dark |
| Phone power bank and cable | $20–$40 | Calling for help when the car is dead |
| Gloves and a few shop rags | $10 | Doing any of the above without ruining your hands |
| Two liters of water | $3 | Waiting in heat; topping a coolant reservoir in a pinch |
Seasonal additions
What you add depends on where you drive, not on what the pre-made kits happen to contain. A driver in Phoenix and a driver in Minneapolis need meaningfully different things.
- Cold-weather states
- Wool blanket, hat and gloves, ice scraper, folding shovel, a bag of cat litter or sand for traction, and washer fluid rated below zero.
- Hot-weather states
- Extra water — a gallon, not a bottle — plus a windshield sunshade, a wide hat and electrolyte packets. Heat strands people faster than cold does.
- Rural or long-distance driving
- A paper map of the region, a gallon jug for coolant or water, a spare serpentine belt if yours is near due, and someone who knows your route.
- Anyone with children or pets
- Snacks, extra water and a plan for shade. A parked car in the sun becomes dangerous within about fifteen minutes.
Documents, fluids and small parts
- Registration and insurance card in the glovebox, plus a photo of both on your phone in case the glovebox is unreachable.
- Roadside assistance number saved in your contacts. Check whether your insurance, credit card or factory warranty already includes towing — plenty of people pay for coverage they already have.
- A quart of the correct engine oil — not a generic quart, but the grade printed on your oil cap. See oil change.
- A gallon of pre-mixed coolant in the correct specification for your car. Never pour cold water into a hot engine.
- Wheel lock key if your car has locking lug nuts. A tire shop cannot help you without it, and it is astonishingly often in a kitchen drawer at home.
- A spare tire check — confirm you actually have one. Many cars built after roughly 2015 shipped with only an inflator kit.
What to do on the shoulder
Gear matters less than positioning. Being struck by passing traffic is by a wide margin the most serious risk in a roadside breakdown, and it is largely avoidable.
Get as far right as possible
Past the white line, onto the shoulder or an exit ramp. If the car will still move at all, getting it 200 feet further to a wider spot or an off-ramp is worth doing.
Hazards on immediately
Turn them on before you slow down, not after you stop. It buys the traffic behind you a few seconds of warning.
Exit on the passenger side
If you must get out, use the door away from traffic and stand well behind a barrier or up a bank — not in front of the car and not between it and the lane.
Set triangles behind the vehicle
Roughly 10, 100 and 200 feet back on a highway, further on a curve or a hill crest so drivers see the warning before they see you.
Usually, stay in the car with the belt on
On a busy freeway shoulder, buckled inside the vehicle is generally safer than standing beside it. Get out and move well away if there is any smell of fuel or sign of smoke — see car overheating.
What you can skip
Prebuilt 120-piece emergency kits pad the count with items that will not help you. Be honest about what you will actually use.
- Tow straps, unless you have a truck and a vehicle with real recovery points. Modern unibody cars have very few safe places to pull from.
- Bottled fuel additives and instant-fix products. Tire sealant in a can is the partial exception, and even then it complicates a proper plug repair afterwards.
- Thin, undersized jumper cables. If you carry cables at all, carry 6-gauge or heavier — the 10-gauge sets in bargain kits will not start a cold V6.
- A full socket set you do not know how to use. The tire iron, the jack and a small multi-tool cover the roadside jobs a non-mechanic can safely do.