What to Check on Your Car Before a Long Road Trip
Check these systems before you leave
Before driving long distances, you need to verify that your brakes, tires, fluids, lights, and wipers will get you safely to your destination. A breakdown on the highway costs money, time, and puts you at risk. Spending 30 minutes on a checklist now prevents hours stranded on the side of the road.
The items below are the ones that fail most often on long trips and cause the most dangerous situations. You do not need special tools — most checks take a flashlight and five minutes. If you find a problem, have a mechanic look at it before you leave, not after you break down.
Key Takeaways
- Check your tire tread depth, pressure, and condition for cracks or bulges before any trip over 100 miles.
- Test your brakes by pressing the pedal firmly in a safe location — it should feel solid, not soft or spongy.
- Top off all fluids: engine oil, coolant, brake fluid, and windshield washer, and check for leaks under the car.
- Turn on your headlights, high beams, brake lights, turn signals, and hazard lights to confirm they all work.
- Replace windshield wipers if they streak or skip, and fill your washer fluid before you leave.
Tires: tread, pressure, and visible damage
Tire failure is the leading cause of blowouts on highways. Check three things: tread depth, air pressure, and physical condition.
For tread depth, use the penny test. Insert a penny into the tread with Lincoln's head upside down. If you can see the top of his head, the tread is too shallow and the tire needs replacement. Do this in at least three spots on each tire, including the outer edges. Uneven wear — bald on one side, thick on the other — means your wheels need alignment; get that done before a long trip.
Check air pressure when the tires are cold, meaning the car has not been driven for at least three hours. The correct pressure is printed on a sticker inside the driver's door frame, not on the tire itself. Use a tire gauge (available at any gas station or auto parts store for under $10) and add air if needed. Underinflated tires overheat on long drives and fail.
Look at each tire for cracks in the sidewall, bulges, or objects stuck in the tread. If you see any of these, do not drive the car — have a mechanic inspect it or replace the tire before you leave.
Brakes: pedal feel and stopping distance
Test your brakes in a safe location with no traffic, like an empty parking lot. Press the pedal firmly and note how it feels. The pedal should be solid and require steady pressure. If it feels soft, spongy, or goes nearly to the floor, your brake fluid is low or your brakes need service — do not take a long trip.
Accelerate to about 20 miles per hour and brake firmly. The car should stop smoothly without pulling to one side. If it pulls left or right, your brakes are uneven and need attention. If you hear grinding or metal-on-metal sounds, your brake pads are worn through and you need new pads before you drive.
Check your brake fluid level by looking at the translucent plastic reservoir under the hood, usually on the driver's side near the back. The fluid should reach the "full" line. If it is low, top it off with the correct type for your car (check your owner's manual or the cap itself), then have a mechanic check for leaks.
Engine fluids: oil, coolant, and washer fluid
Low fluids cause overheating, engine damage, and breakdowns. Check these three before you leave.
Engine oil: Turn off the engine and wait five minutes. Pull out the dipstick (a long metal rod under the hood), wipe it clean with a paper towel, reinsert it fully, then pull it out again. The oil level should be between the minimum and maximum marks. If it is low, add the correct type and weight for your car — check your owner's manual or the oil cap. On a long trip, bring an extra quart with you.
Coolant: Look at the plastic coolant reservoir (usually translucent and marked with minimum and maximum lines). The level should be between these lines when the engine is cold. If it is low, top it off with the correct coolant type. Do not open the radiator cap itself — the system is pressurized and can burn you. If coolant level drops again within a few days, you have a leak and need a mechanic before a long drive.
Windshield washer fluid: This is the easiest to check and refill. Open the washer fluid reservoir under the hood and look inside. If it is empty or nearly empty, buy washer fluid at any gas station or auto parts store and fill it. Bring an extra gallon in your car for the trip.
Lights: headlights, brake lights, and turn signals
Broken lights make you invisible to other drivers and are illegal to drive with. Check all of them before you leave.
Turn on your headlights and walk around the car to confirm both low beams work. Switch to high beams and check again. Turn on your brake lights by pressing the brake pedal while someone watches the rear of the car, or back up to a reflective surface like a garage door and watch the reflection. Test both left and right turn signals by turning the steering wheel and watching the front and rear lights blink. Turn on your hazard lights and confirm all four corners flash.
If any light is out, replace the bulb yourself (most are simple — check your owner's manual for location and type) or have a mechanic do it. Bring spare bulbs in your car in case one burns out during the trip.
Windshield wipers and visibility
Worn wipers leave streaks or skip across the glass, reducing visibility in rain or snow. If your wipers do either, replace them before you leave. Wiper blades are inexpensive (usually $10 to $20 each) and take two minutes to swap — auto parts stores will install them for free if you buy them there.
While you are checking wipers, look at your windshield for cracks or chips. A small chip can spread into a crack during a long drive due to temperature changes and vibration. If you have a large crack in your line of sight, have it repaired or replaced before you go.
Clean your windshield inside and out before you leave. Dust and film reduce visibility, especially at night or in bright sun. Use glass cleaner and newspaper or microfiber cloths.
Battery, belts, and hoses
A dead battery strands you far from home. Look at your battery terminals (the metal posts where cables connect) and check that they are clean and tight. If they are corroded (white, blue, or green crusty buildup), disconnect the negative cable first, then clean the terminals with a wire brush and baking soda mixed with water. Reconnect the negative cable last.
Pop your hood and look at the rubber belts and hoses. Belts should be smooth with no cracks or fraying. Hoses should be firm, not soft or mushy, and should not leak. If you see cracks, fraying, or leaks, have a mechanic inspect them before you leave — a broken belt or burst hose will leave you stranded.
Documents and emergency supplies to bring
Before you leave, gather your vehicle registration, proof of insurance, and driver's license. Keep these in an easy-to-reach location in case you are stopped or need to show them to a mechanic.
Pack a basic emergency kit: jumper cables or a portable jump starter, a flashlight with extra batteries, a tire plug kit or spare tire (confirm your spare is inflated), a jack, a lug wrench, a basic tool kit, flares or reflective triangles, and a first aid kit. Include phone numbers for your roadside assistance program (if you have one) and a trusted mechanic. Bring water, snacks, and a phone charger.
Frequently Asked Questions
How far in advance should I do this checklist?
Do it the day before you leave or the morning of your trip. If you find a problem that needs a mechanic, you want time to get it fixed. If you check a week early and something fails in the meantime, you will have to check again anyway.
What if my car fails one of these checks?
Do not drive long distances. Have a mechanic look at the problem before you leave. A breakdown on the highway is more expensive and dangerous than delaying your trip by a day or two.
Do I need to check my transmission fluid?
Some cars have transmission fluid you can check; others are sealed and require a mechanic. Check your owner's manual. If your transmission is low, you have a leak and need a mechanic before a long trip.
Should I get a full inspection before a road trip?
If your car is older or has high mileage, a mechanic's inspection is worth the cost. If your car is newer and well-maintained, this checklist covers the critical items. Either way, do not skip the checks above.
What should I do if something breaks during the trip?
Pull over safely, turn on your hazard lights, and call roadside assistance or a tow truck. Do not attempt repairs on the highway unless it is something simple like a flat tire in a safe location. Stay in your car with the doors locked if you are on a busy road.