How Does Blind-Spot Monitoring Work?

The blind spot of a car, truck, or SUV is one of the most dangerous places for other drivers. This area is a space near the rear of your vehicle which isn’t visible in your sideview or rearview mirrors. To see what’s in your blind spot, you must turn your head to look in that area. This involves taking your eyes off the road in front of you. Thankfully, blind-spot monitoring is a safety feature that can help you avoid an accident and know what’s happening in this space.

Why is blind-spot monitoring important?

Blind-Spot Monitoring Warning Indicator alerts a driver to a vehicle in their blind area
Blind-Spot Monitoring Warning Indicator | Shutterstock

As the name states, this road area isn’t visible to you or your mirrors during your drive. The larger the vehicle you drive, the bigger your blind spot is. This is one reason it’s extremely difficult for semi-trucks to see you. While many vehicles have small blind-spot mirrors attached to the large sideview mirrors, a monitoring system is better for your safety.

How does this feature work?

Autotrader tells us the blind-spot monitoring system uses a set of sensors located on the outside of the car to monitor the blind area. If the sensors detect a car in the space, a small light informs you that a vehicle is present. These lights are typically on the inside of the front doors or in the side mirrors.

If you turn on your signal to indicate your desire to make a lane change, the feature sounds an audible alert when a vehicle is present in the blind area. Some cars have a blind-spot intervention system, which won’t allow you to make a lane change when a vehicle or obstacle is detected in the blind area of your car.

Where are the sensors for blind-spot monitoring?

The Blind Spot of a Semi is much larger than a car
Blind Spot of a Semi | Shutterstock

You want to ensure the sensors stay clean to allow your system to work right for you. This means you need to know where they are on your car. Consult your owner’s manual for your vehicle, but My Car Does What tells us these sensors are either in the sideview mirrors or under the rear bumpers. The detection area covers one lane width on both sides of the car to help keep you safer during your drive.

Do all vehicles offer this safety feature?

No, some don’t offer it, and many do not have it as part of the standard package. More vehicles have blind-spot monitoring than ever before, but even as late as 2020, this feature was optional on some vehicles. If you’re searching for a pre-owned vehicle and want this feature, you might be in for a surprise. Consumer Reports tells us these vehicles either didn’t offer blind-spot monitoring in 2020, or it was only optional:

  • Ford F-150 – Optional
  • Chevrolet Silverado 1500 – Optional
  • Ram 1500 – Optional
  • Toyota RAV4 – Optional
  • Honda CR-V- Optional
  • Toyota Camry – Optional
  • Chevrolet Equinox – Optional
  • Honda Civic – Not Available
  • Honda Accord – Optional
  • Toyota Corolla – Optional
  • Toyota Tacoma – Optional

How much does it cost to add blind-spot monitoring?

A Blind-Spot Mirror can be helpful, but not as good as the monitoring system
Blind-Spot Mirror | Shutterstock

The cost to add this feature to a vehicle that doesn’t already include it ranges from $250 to $500. It’s a little less for cars that come with it and typically part of the safety package for newer vehicles. Unfortunately, some automakers still don’t offer this alert system as a standard feature requiring consumers to move up to higher trims to enjoy the benefits.

Is lane departure warning the same as blind-spot monitoring?

No, these are two different safety features for your vehicle. Extreme Tech tells us that lane departure warning alerts you that your car is about to move out of the lane and offers a warning to get back into the lane. This is different from blind-spot monitoring, which only offers an audible warning when you indicate your desire to change lanes while a vehicle is in your blind area.

If you want to learn about more safety features, check out the next article to tell you more about lane departure warning.

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