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What is hill start assist and how does it work?

minute read

    Quick insights

    • Hill-start assist is a technology in modern vehicles to help your car accelerate from a stop when you’re on an incline.
    • The main benefits of hill-start assist systems are improved safety and comfort when driving.
    • Hill-start assist can be found in many vehicles, but the driver plays a key role in safe vehicle operation.

    Today’s cars are advanced, and many of them are equipped with the latest types of technology. One of those is hill-start assist, a feature that has become widely adopted in vehicles. In this article, we’ll explain how this feature works and learn more about its utility.

    What is hill-start assist?

    Hill-start assist is a system that can prevent a vehicle from rolling backward when you release the brakes on an incline. The system normally activates when you come to a stop on a hill and stays engaged after you release the brake. This should keep your car in place and provide enough time for you to press the accelerator, then move on comfortably.

    How does hill-start assist work?

    Hill-start assist uses special sensors within a vehicle’s mechanical systems to detect that you’re on an incline. Once detected, the system engages and stops the vehicle from rolling backward.

    Here’s how a hill-start assist system typically works:

    • Detection: The system’s sensors might be connected to one or more parts of the vehicle to detect when it’s on an incline. That could include the engine, accelerator, suspension, brakes or more.
    • Activation: When you press and hold the brake pedal, hill-start assist will also engage the vehicle’s brakes to hold it in place.
    • Retention: Once you release the brake pedal, the brakes aren’t immediately disengaged. The hill-start assist system retains brake pressure for a brief period. In this time you can transition from the brake pedal to the accelerator without the risk of rolling backward.
    • Acceleration: Once the system detects the intent to move forward, it releases the brake pressure. The engine can build some torque as it normally does when you hold the accelerator, and the vehicle can proceed smoothly.
    • Deactivation: Hill-start assist normally deactivates either when the vehicle reaches a certain speed, after a certain amount of time or once an incline is no longer detected.

    The exact operation of hill-start assist systems may vary between vehicle makes and models. Some vehicles may also offer manual activation options and give you more or less control of the system’s behavior.

    Benefits of hill-start assist

    The automatic nature of most hill-start assist systems can offer some confidence when driving and contribute to overall safety. The short period you get to transition from stopped to starting on an incline is useful for everyone. Otherwise, gravity takes over. When cars roll back unexpectedly, fender-benders and more disastrous accidents could occur, particularly if a vehicle is towing a heavy load.

    Potential disadvantages of hill-start assist

    Hill-start assist is generally beneficial but not without some downsides:

    • Extra cost: Hill-start assist might be more common in vehicles than ever before. However, the system could still be considered an extra feature and increase the price you’d pay for a vehicle.
    • Incompatibility with certain terrain: In very rough terrain or off-road situations, hill-start assist may not function effectively or be suitable for the driving conditions. This means it’s on the driver to maneuver the vehicle’s starts and stops.
    • False sense of security: Ultimately, accidents or damage to all vehicles on the road aren’t completely unavoidable with hill-start assist. It can create overconfidence when driving on hills and cause someone to mishandle their vehicle, perhaps with the handbrake or clutch.

    Cars with hill-start assist

    Initially, hill-start assist was found in higher-end vehicles and luxury brands. However, automotive technology has advanced. Hill-start assist and many other safety features have become more standard across all types of vehicles, including:

    What people did before hill-start assist

    Before the advent of hill-start assist systems, drivers relied on manual techniques to prevent rollback when starting on a hill. Here some of those common practices:

    • Clutch control: Drivers could use precise clutch control on a hill to prevent a vehicle from rolling back. By partially engaging the clutch on an incline, then transitioning to the accelerator, you can prevent a vehicle from rolling backward.
    • Handbrake technique: Drivers would engage the handbrake (parking brake) before releasing the foot brake while stopped on a hill. Once the clutch engaged and the vehicle began moving forward, the driver would release the handbrake and timely press the gas.
    • The double-pedal: Some drivers use both feet, keeping each one prepared to press the brake or accelerator depending on the situation. Good coordination is especially important on hills to release the brake slowly and press the gas to create forward momentum.

    Hill-start assist technology has made navigating inclines more comfortable for modern drivers. However, understanding manual techniques like those above is still valuable for situations when hill-start assist is not available or reliable.

    In summary

    Hill-start assist might also be called hill-start assist control or hill-hold control. The feature is in many modern vehicles and can improve safe driving for everyone sharing the road. Hill-start assist systems’ general designs help drivers when they’re starting from a stopped position on an incline or hill.

    The system is more common in today’s vehicles but might still be considered an extra feature. If you’re curious, ask about it the next time you’re preparing to buy a car.

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