A blind spot is an area around your vehicle that you cannot see in your mirrors or by looking over your shoulder
Every vehicle has blind spots — zones where another car, motorcycle, or cyclist can be completely hidden from your view. They exist because your side mirrors and rearview mirror cannot show you everything behind and beside your car. The most dangerous blind spots are on both sides of your vehicle, roughly from your rear door to the back corner. A vehicle traveling in that zone will not appear in any of your mirrors, and you may not see it even if you turn your head.
Blind spots are larger on trucks, vans, and SUVs than on sedans, because taller vehicles block more of the view behind them. The size and shape of your blind spot also changes depending on where you sit in the driver's seat, how your mirrors are angled, and the size of the vehicle next to you. A motorcycle or small car can hide completely; a large truck cannot.
Understanding where your blind spots are and checking them before you change lanes or turn is one of the most direct ways to prevent a collision. Many crashes happen because a driver did not see another vehicle in a blind spot and moved into its path.
Key Takeaways
- Blind spots exist on both sides of your vehicle, roughly from the rear door back, and cannot be seen in any mirror.
- The size of a blind spot depends on your vehicle type, mirror angle, and the size of the vehicle next to you.
- Checking your blind spot by turning your head before changing lanes or turning is the most reliable way to avoid a collision.
- Newer vehicles may have blind spot warning systems that alert you when another vehicle is in the zone, but these are not a replacement for looking.
Where blind spots are located on your vehicle
The primary blind spot on each side of your car is located behind the rear door and extends toward the back corner of the vehicle. This zone is hidden from your side mirror because the mirror is angled to show the lane beside you, not the area directly behind your rear bumper. It is also hidden from your rearview mirror because the body of your own car blocks the view.
There is also a smaller blind spot directly behind your vehicle, below the rear window. This is why backing up slowly and checking behind you is important, especially in parking lots or driveways where pedestrians or small objects may be present.
Some drivers do not realize there is a blind spot in front of the vehicle as well. The hood of your car, the A-pillars (the vertical supports on either side of the windshield), and the dashboard can block your view of pedestrians, cyclists, or small vehicles directly ahead, especially at intersections or when turning.
How to check your blind spot before changing lanes
The most reliable method is to turn your head and look directly into the blind spot zone before you move. This takes about one second and should happen after you have checked your mirrors but before you signal or steer. The sequence is: check your rearview mirror, check the side mirror on the side you plan to move toward, then turn your head to look at the blind spot itself.
Signal your intention to change lanes before you move, but do not assume that signaling alone will protect you. Other drivers may not see your signal, or they may not react in time. The head check is your final confirmation that the lane is clear.
If you are driving a truck, van, or large SUV, remember that your blind spot is significantly larger than that of a sedan. You may need to move your head further or check the blind spot earlier in your lane change to be certain the area is clear.
Why blind spots cause crashes
Most blind spot collisions happen during lane changes on highways or multi-lane roads. A driver checks the mirrors, sees the lane is clear, and begins to move. At the same moment, another vehicle that was hidden in the blind spot is also moving into that same space. The two vehicles collide before either driver realizes the other was there.
Blind spot crashes are often serious because they happen at highway speeds and the vehicles are traveling in nearly the same direction. The impact is usually a sideswipe or a glancing blow that can cause a vehicle to spin or roll, especially if one vehicle is larger or heavier than the other.
Motorcyclists and cyclists are at particular risk because they are smaller and fit entirely within a blind spot. A driver may not see them even if they look, especially in poor light or bad weather. Drivers of motorcycles and bicycles should assume they are in a blind spot whenever they are beside a vehicle and should not linger in that zone.
Blind spot warning systems and how they work
Many newer vehicles come with a blind spot warning system that uses radar or cameras to detect vehicles in the blind spot zone. When another vehicle enters the blind spot, the system alerts the driver with a light on the side mirror, a beep, or a vibration in the seat. Some systems will also prevent you from changing lanes if a vehicle is detected in the blind spot.
These systems are helpful, but they are not perfect. They can fail in heavy rain, snow, or fog. They may not detect motorcycles or bicycles. They can also give false alarms if the system is dirty or misaligned. For these reasons, a blind spot warning system should never replace the habit of turning your head to look.
If your vehicle does not have a blind spot warning system, you can purchase an aftermarket mirror or camera system that provides a wider field of view. However, the most cost-effective and reliable method remains the straightforward head check.
How to adjust your mirrors to minimize blind spots
Proper mirror adjustment can reduce the size of your blind spots, though it cannot eliminate them entirely. For your side mirrors, angle them so that you can just barely see the side of your own vehicle on the inside edge of the mirror. This pushes the mirror's view further out and reduces the blind spot zone.
Some drivers prefer to angle the side mirrors even further out, so they cannot see their own vehicle at all. This widens the field of view and reduces the blind spot further, but it means you lose the reference point of your own car. Either method works; the key is to be consistent so you know what your mirrors show.
The rearview mirror should be angled so you see the entire rear window and an equal amount of sky and road. Adjust it before you drive, not while you are moving. Remember that even with perfect mirror adjustment, you will still have a blind spot that requires a head check to see.
Blind spots in different driving situations
On the highway, blind spots are most dangerous during lane changes at high speed. Check your blind spot earlier than you think you need to, because vehicles are moving faster and closing the distance quickly. If you are merging onto a highway, check the blind spot of the lane you are entering, not just the lane you are leaving.
In city driving and at intersections, blind spots matter when you are turning. A vehicle, cyclist, or pedestrian in your blind spot may be crossing the intersection while you are turning. Always slow down before turning, look in the direction you are turning, and check your blind spot on that side.
In parking lots, blind spots are dangerous when backing up or when another vehicle is backing out of a space next to you. Move slowly, look behind you, and be prepared to stop. If you cannot see clearly, get out and look, or ask someone to guide you.
Frequently Asked Questions
Can I eliminate my blind spot completely?
No. The shape and size of your vehicle will always create zones that cannot be seen in mirrors alone. You can reduce blind spots through mirror adjustment and warning systems, but the only way to see a blind spot is to turn your head and look directly at it.
Why do trucks have bigger blind spots than cars?
Trucks are taller and longer, so they block more of the view behind them and beside them. A vehicle can hide in a truck's blind spot more easily than in a sedan's blind spot. Truck drivers must check their blind spots more carefully and may need to move their head further to see the entire zone.
What should I do if another driver is in my blind spot?
Do not change lanes or turn. If you are already moving, continue straight and let the other vehicle pass. If you are stopped, wait until the vehicle has moved clear of your blind spot before you proceed. Never assume another driver sees you just because you see them.
Do blind spot mirrors really work?
Aftermarket blind spot mirrors can expand your field of view and help you see vehicles in the blind spot zone. However, they work best in good light and may distort the image or create a false sense of distance. They are a helpful tool but should not replace the habit of turning your head to look.
Is it illegal to not check your blind spot?
Most states do not have a specific law about checking blind spots, but they do have laws against unsafe lane changes and turns. If you change lanes or turn without checking and cause a crash, you can be cited for unsafe driving or failure to maintain your lane. Checking your blind spot is the safest and legally sound practice.