Why Can't You Use Cruise Control in the Rain? Understanding the Risks and When It's Safe

Why Can't You Use Cruise Control in the Rain? Understanding the Risks and When It's Safe

It was a classic scenario. I was on a long stretch of highway, the rain was coming down in sheets, and for a moment, I was tempted to engage the cruise control. After all, I wasn't going particularly fast, and the road seemed relatively straight. But then, a flicker of caution, a memory of a driving instructor's stern warning, stopped me. Why can't you use cruise control in the rain? It’s a question that many drivers ponder, especially when precipitation turns a familiar drive into a more precarious one. The short answer is that while modern cruise control systems have become more sophisticated, using them in wet conditions significantly increases the risk of losing control of your vehicle.

As a driver who’s navigated my fair share of downpours, I’ve learned that the seemingly simple act of engaging cruise control in the rain is a gamble with your safety and the safety of others. It’s not just about the potential for a hydroplaning incident; it’s about how the system interacts with compromised road conditions and the inherent limitations of automated speed management when traction is a question mark. Let's delve into the nuanced reasons why this seemingly convenient feature becomes a potential hazard when the heavens open up.

The Core Issue: Reduced Traction and Unpredictable Vehicle Behavior

The fundamental reason why you can't reliably use cruise control in the rain boils down to a single, critical factor: reduced traction. When the roads are wet, the tires of your vehicle have significantly less grip on the asphalt. This diminished grip affects your car's ability to accelerate, brake, and steer effectively. Cruise control, by its very nature, is designed to maintain a set speed. It does this by actively managing the throttle and, in some advanced systems, even the brakes. However, in wet conditions, the system's ability to react to changes in traction becomes compromised, leading to potentially dangerous situations.

Think about it this way: when you're driving manually in the rain, you're constantly making micro-adjustments. You feel the road through the steering wheel and your seat, and your brain interprets subtle cues about grip. If you feel a slight slip, you instinctively ease off the gas, make smaller steering inputs, or apply the brakes more gently. Cruise control, even the most advanced adaptive systems, operates on pre-programmed algorithms and sensor data. While these sensors are sophisticated, they can struggle to accurately assess and react to the rapidly changing and often unpredictable nature of tire grip on a wet surface.

One of the most common and terrifying consequences of using cruise control in the rain is hydroplaning. This happens when a layer of water builds up between your tires and the road surface, causing your tires to lose contact with the asphalt. At this point, your vehicle is essentially riding on water, and you have little to no steering control. If cruise control is engaged, and the system detects a slight decrease in speed due to the hydroplaning, it might try to compensate by applying more throttle. This sudden application of power on a surface with no traction can exacerbate the hydroplaning situation, leading to a complete loss of control. The car could spin, drift into other lanes, or even leave the roadway.

I recall one instance, a few years back, driving on I-70 through Missouri. It wasn't a torrential downpour, but a steady, persistent rain had left the highway slick. I was on a gentle curve, and I saw a car ahead of me in the middle lane suddenly drift. The driver had cruise control on, and as their tires encountered a patch of standing water, the car hydroplaned. Thankfully, the driver was able to regain some control, but it was a stark reminder of how quickly things can go south when automation meets compromised traction. The cruise control, trying to maintain speed, likely applied a bit too much power at the worst possible moment, contributing to the loss of control.

How Cruise Control Works and Why Rain Disrupts It

To truly understand why cruise control and rain are a bad combination, it's helpful to have a basic grasp of how these systems function. At its core, cruise control is designed to automate the process of maintaining a set vehicle speed. When you engage it, you typically set a desired speed. The system then uses a control module to monitor your actual speed and compare it to the set speed. If your speed drops (perhaps going uphill or encountering resistance), the control module signals the engine to apply more throttle. If your speed increases (going downhill), it might reduce throttle or, in more advanced systems, even apply the brakes to maintain the set speed.

Basic Cruise Control: This is the most rudimentary form. It primarily controls the throttle. In wet conditions, if the system needs to accelerate to maintain speed, it might push the tires too hard on a slick surface, leading to wheel spin and a loss of traction. The driver's intervention is crucial here to modulate the throttle appropriately.

Adaptive Cruise Control (ACC): This is where things get more complex and, arguably, more problematic in the rain. ACC systems use radar, lidar, or cameras to detect vehicles ahead and adjust your speed to maintain a safe following distance. They can also brake and accelerate automatically. While incredibly useful in clear weather, the sensors used by ACC systems can be affected by heavy rain. Water on the windshield can obscure camera views, and heavy rain can interfere with radar signals. More importantly, ACC systems rely on precise data about the vehicle's speed and the surrounding environment to make decisions. When traction is compromised, this data becomes less reliable. Imagine the system is trying to maintain a set distance from the car in front. If that car brakes suddenly on a wet road, and your ACC system doesn't get a perfect reading or can't brake effectively due to low traction, a collision could occur.

Lane Keeping Assist and Other Advanced Systems: Many modern vehicles combine cruise control with other driver-assistance features like Lane Keeping Assist (LKA) and Lane Centering. These systems use cameras to identify lane markings. Heavy rain can make lane markings difficult or impossible to see, both for the human driver and the vehicle's sensors. If your cruise control is engaged and your car’s lane-keeping system loses sight of the lane markings due to rain, it could lead to the vehicle drifting out of its lane, a situation made all the more dangerous if the driver is relying on the system to maintain speed and position.

My own experience with ACC has been overwhelmingly positive in fair weather. It's a marvel of engineering. However, I once experienced a slightly unnerving moment on a misty highway where the system seemed a bit hesitant to react to a slowing vehicle ahead. It wasn't a critical failure, but the slight delay made me acutely aware that the technology, however advanced, is still dependent on clear, consistent data. In heavy rain, that consistency is precisely what's lacking.

The Dangers of Cruise Control in Rain: A Detailed Breakdown

Let's get granular about the specific risks associated with using cruise control when the roads are wet:

• Hydroplaning and Loss of Control: As mentioned, this is the most significant risk. When tires lose contact with the road, they can't effectively steer or brake. If cruise control is engaged and tries to accelerate or maintain speed, it can worsen the situation. The vehicle essentially becomes a runaway object, and the driver's ability to correct it is severely hampered.
• Inability to React to Sudden Braking: If the vehicle in front of you brakes suddenly on a wet road, even with Adaptive Cruise Control, there's a risk. The ACC's braking might be less effective due to reduced traction. Additionally, the system might not be programmed to anticipate the extreme reduction in braking efficiency that occurs on wet surfaces. Human drivers, on the other hand, can intuitively gauge stopping distances and brake force needed.
• Struggles with Uphill and Downhill Slopes: Cruise control's job is to maintain a set speed. On a wet uphill slope, if the system needs to apply more throttle, it risks wheel spin. On a wet downhill slope, if the system needs to brake, its effectiveness is significantly reduced. This means the vehicle could accelerate beyond the set speed, or its braking might be insufficient, both of which are dangerous in slippery conditions.
• Compromised Sensor Functionality (ACC and Advanced Systems):
  • Radar/Lidar: Heavy rain can scatter or attenuate radar and lidar signals, leading to inaccurate readings or complete loss of detection of vehicles or obstacles.
  • Cameras: Water spray from other vehicles, condensation on the windshield, and the reduced visibility of lane markings can blind the cameras used by ACC and LKA systems.
• Reduced Effectiveness of Stability Control Systems: While modern cars have advanced Electronic Stability Control (ESC) systems that can help prevent skids, they still rely on traction. If a vehicle is already hydroplaning, ESC might have limited ability to regain control. Using cruise control in these conditions can put the ESC system in a losing battle.
• False Sense of Security: Drivers might become complacent when using cruise control, assuming the car is handling the speed management. This can lead to reduced driver engagement, making them less prepared to intervene when necessary, especially in adverse weather.
• Difficulty in Making Smooth Corrections: If the cruise control system over-corrects (either accelerating too much or braking too abruptly on a slick surface), it can induce a skid. A human driver would typically make smoother, more nuanced adjustments.

I've heard anecdotal accounts from professional drivers and mechanics who have witnessed the dramatic failure of automated systems in poor weather. One story involved a delivery truck whose adaptive cruise control, despite the rain, attempted to maintain speed. When the truck in front braked hard, the system's response was not quick or forceful enough to compensate for the slick road, leading to a fender-bender. This highlights that even in commercial settings, where vehicles might be equipped with more robust systems, the fundamental physics of reduced traction remain a critical challenge.

When is it *Potentially* Safe to Use Cruise Control in the Rain?

While the general advice is to avoid cruise control in the rain, there are very specific, limited circumstances where it *might* be considered, with extreme caution. These are scenarios where the risks are minimized, but never entirely eliminated. I would categorize these as follows:

• Very Light Drizzle, Dry-Looking Road Surface: If it's barely raining, and the road surface still appears mostly dry with only a slight sheen, the traction reduction is minimal. In this case, using basic cruise control on a straight, flat highway might be considered. However, even a light sprinkle can quickly lead to slick conditions.
• Excellent Road Conditions and Visibility: This means no standing water, no puddles, and very clear visibility. The road should be free of debris that could be made more dangerous by water.
• Extremely Straight and Flat Terrain: Avoid using cruise control on hills or curves, even in light rain. These maneuvers require more precise control over acceleration and deceleration, which are the very things compromised by wet conditions.
• Low Traffic Density: The fewer other vehicles around, the less likely you are to encounter unexpected braking situations.
• Driver Vigilance is Paramount: Even in these "safer" scenarios, your eyes must be on the road, and your foot must be hovering near the brake pedal, ready to disengage cruise control instantly. You are essentially using it as a very light assist, not as a system to zone out with.

I personally would still err on the side of caution. The few minutes saved by not manually controlling speed are simply not worth the potential cost of an accident. My personal philosophy leans towards maintaining complete control when conditions are less than ideal. I've found that even a light rain can make the road surface surprisingly slick, especially on older asphalt or when oil and grime mix with the water.

Consider this table of road condition severity versus cruise control advisability:

This table simplifies the decision-making process. Even if all other factors seem favorable, the moment you see standing water or the road surface is clearly wet, it's time to disengage any automated speed control. The nuance of how much water is "too much" is something that develops with experience, but erring on the side of caution is always the wisest approach.

The Role of Tires and Vehicle Maintenance

It's crucial to remember that your tires play a pivotal role in how your vehicle performs in the rain, and this directly impacts the safety of using any form of cruise control. Worn-out tires, or tires not designed for wet-weather performance, can dramatically reduce traction, making even light rain a significant hazard.

Tire Tread Depth: The grooves in your tires are designed to channel water away from the contact patch between the tire and the road. As tires wear down, this tread depth decreases, reducing their ability to evacuate water. When tread depth is insufficient, hydroplaning becomes much more likely. The "penny test" is a common way to check tread depth: insert a penny into the deepest groove with Lincoln's head facing down. If you can see the top of Lincoln's head, your tread depth is likely too low.

Tire Type and Condition: All-season tires offer a compromise between performance in various conditions. However, dedicated winter tires or performance tires designed for wet grip might offer superior performance in rain. Additionally, ensuring your tires are properly inflated is critical for maintaining the correct contact patch with the road. Underinflated or overinflated tires can alter handling characteristics and increase the risk of hydroplaning.

Vehicle Maintenance: Beyond tires, ensuring your vehicle's braking system and suspension are in good working order is paramount. Faulty brakes or worn suspension components can exacerbate issues with traction and control, making any attempt to use cruise control in the rain even more dangerous.

I once had a friend who was adamant about using cruise control even in a moderate rain. He argued that his car was relatively new and had all the latest safety features. However, when I looked at his tires, they were noticeably bald. It was a recipe for disaster waiting to happen. After a long talk, he finally agreed to get new tires, and the difference in his car's handling in the wet was remarkable. It was a powerful lesson that technology can only do so much; the fundamental physics of the road and your vehicle's contact with it are king.

Driver Responsibilities and Best Practices in the Rain

Ultimately, the decision to use or not use cruise control in the rain rests with the driver. While technology can assist, it cannot replace the need for vigilance, judgment, and responsible driving habits. Here are some key best practices for driving in the rain:

• Disengage Cruise Control Immediately: As soon as you encounter rain, or even the anticipation of rain (dark clouds, changing road surface appearance), disengage your cruise control. Manual control is essential.
• Increase Following Distance: Wet roads significantly increase braking distances. Doubling or even tripling your normal following distance is a good rule of thumb. This gives you more time to react if the vehicle ahead brakes suddenly.
• Reduce Speed: Driving at or near the speed limit in rain is often too fast. Slow down to a speed where you feel in control and can safely react to your surroundings.
• Smooth Inputs: Avoid sudden acceleration, braking, or sharp steering movements. These abrupt actions can easily break traction on a wet surface.
• Be Aware of Standing Water and Puddles: Try to avoid driving through deep puddles or standing water, as this is where hydroplaning is most likely. If you must drive through them, do so slowly and straight.
• Turn on Headlights: Even in daylight, headlights improve your visibility to other drivers and make your vehicle more visible.
• Turn off Cruise Control and Other Automated Systems: This cannot be stressed enough. Rely on your own senses and reactions.
• Scan for Hazards: Pay extra attention to the road ahead for potential hazards like debris, potholes hidden by water, or other vehicles that may be struggling with traction.
• Test Your Brakes Periodically: After driving through water, gently apply your brakes to help dry them out and ensure they are functioning correctly.

I often think of driving in the rain as a form of dance. You have to be in tune with the rhythm of the road, anticipating its moves and responding with grace and precision. Cruise control, in this analogy, is like trying to have a dance partner who insists on moving at a fixed pace, regardless of the music's tempo or the floor's slipperiness. It disrupts the flow and can lead to a stumble.

Frequently Asked Questions About Cruise Control and Rain

How does rain affect tire grip?

Rain significantly reduces tire grip by introducing a layer of water between the tire and the road surface. This layer of water acts as a lubricant, diminishing the friction that allows your tires to effectively transmit forces for acceleration, braking, and steering. The less tread depth a tire has, the less effectively it can channel water away, making it more prone to hydroplaning, where the tire completely loses contact with the road and rides on the water.

The severity of grip reduction depends on several factors:

• Water Depth: Even a thin film of water can reduce grip considerably, but standing water and puddles pose a much greater risk of hydroplaning.
• Tire Tread Depth and Design: Tires with less tread depth or those with tread patterns not optimized for water evacuation will offer less grip.
• Tire Pressure: Improper tire inflation can alter the tire's contact patch with the road, affecting its ability to grip.
• Speed: The faster you drive, the harder it is for tires to displace water, increasing the likelihood of hydroplaning.
• Road Surface: Some road surfaces are naturally more prone to becoming slick when wet due to their composition or accumulated oil and grime.

Essentially, rain turns a predictable, grippy surface into an unpredictable, slippery one, demanding constant, nuanced adjustments from the driver – adjustments that automated systems like cruise control are not always equipped to make reliably.

Why is Adaptive Cruise Control (ACC) particularly risky in the rain?

Adaptive Cruise Control (ACC) is designed to be more sophisticated than standard cruise control, but this very sophistication can be a liability in rainy conditions. ACC systems rely heavily on sensors (radar, lidar, cameras) to detect vehicles ahead and their movements. In the rain:

• Sensor Interference: Heavy rain can interfere with the signals from radar and lidar sensors, potentially causing them to misinterpret distances or fail to detect vehicles altogether. Water droplets can scatter radar beams, and dense rain can absorb lidar signals.
• Visual Obstructions: Cameras used by ACC systems can be significantly impaired by water sprayed from other vehicles, condensation on the windshield, or the reduced visibility of lane markings. This means the system might not "see" what it needs to see to function correctly.
• Compromised Braking Effectiveness: While ACC can apply brakes, its ability to do so effectively is directly tied to the available traction. On a wet surface, the braking force the system can apply without causing a skid is much lower than on dry pavement. If the car in front brakes suddenly, the ACC might not be able to stop in time, especially if its sensors are also compromised by the rain.
• Unforeseen Road Conditions: ACC systems are programmed based on expected driving scenarios. They might not be adequately programmed to account for the rapid and drastic changes in traction that can occur with hydroplaning or sudden loss of grip. A human driver can often feel a slight slip and react preemptively, whereas an ACC system might only react once a significant deviation in speed or wheel rotation is detected, which could be too late.

Therefore, while ACC aims to enhance safety and comfort, its reliance on clear sensor data and predictable traction makes it a system that should generally be disengaged when driving in wet conditions.

Can cruise control cause a car to hydroplane?

Cruise control itself doesn't directly *cause* a car to hydroplane, but it can exacerbate the situation and significantly reduce your ability to recover if hydroplaning occurs. Here's how:

Hydroplaning happens when the tires lose contact with the road due to a layer of water. Once hydroplaning begins, your steering and braking are severely compromised. If cruise control is engaged, and the car detects a slight loss of speed (which happens during hydroplaning), its natural instinct is to compensate by applying more throttle to maintain the set speed. On a surface where there is no traction, this sudden application of power can actually make the hydroplaning worse, causing the wheels to spin faster and potentially leading to a complete loss of control, such as a spin or drift.

A human driver, feeling the loss of control, would typically lift off the accelerator and avoid sudden braking. Cruise control, however, operates on programmed logic. If that logic dictates acceleration to maintain speed, it can inadvertently worsen a hydroplaning event. Therefore, while cruise control isn't the initial cause, its operation in a hydroplaning scenario can turn a potentially recoverable situation into a dangerous one.

What are the main differences between basic cruise control and adaptive cruise control in rainy conditions?

The primary difference lies in their operational focus and the technology they employ, which leads to different risk profiles in the rain:

• Basic Cruise Control:
  • Function: Maintains a set speed. It primarily controls the throttle and may use brakes for downhill speeds.
  • Rain Risk: Its main risk is in attempting to accelerate on a slick surface, potentially causing wheel spin, or being unable to adequately slow down on a wet downhill slope. It does not account for other vehicles.
• Adaptive Cruise Control (ACC):
  • Function: Maintains a set speed *and* a set distance from the vehicle ahead, using sensors to adjust speed, brake, and accelerate.
  • Rain Risk: ACC adds the complexity of sensor reliability in rain and the system's ability to brake effectively on wet surfaces. The sensors can be blinded or interfered with by rain, leading to incorrect assessments of the traffic situation. Its braking response, while automatic, is still subject to the laws of physics regarding reduced traction on wet roads.

In essence, basic cruise control is a simpler system that has fewer points of failure related to external conditions but still poses risks due to its basic function on slippery surfaces. ACC, while more advanced, introduces new vulnerabilities related to sensor performance and the complex interplay of automated braking with low traction. Both systems, however, require the driver to be prepared to take over immediately when conditions deteriorate due to rain.

Should I turn off my car's traction control or stability control in the rain?

Absolutely not. Traction Control Systems (TCS) and Electronic Stability Control (ESC) are your most valuable allies in rainy conditions. You should *never* turn them off unless explicitly instructed to do so by your vehicle's owner's manual for a very specific, usually off-road or extreme situation, which does not apply to driving on a wet road.

Here's why they are crucial:

• Traction Control (TCS): If your wheels begin to spin (e.g., during acceleration on a slick surface), TCS automatically reduces engine power or applies the brakes to the spinning wheel(s) to restore traction. This is precisely what you want when driving in the rain to prevent losing control.
• Electronic Stability Control (ESC): ESC takes it a step further. If the system detects that your car is starting to skid or lose directional control (e.g., oversteering or understeering), it can automatically apply individual brakes to different wheels and may reduce engine power to help you regain control of the vehicle's path. This system is designed to prevent or mitigate dangerous skids that are much more likely in wet weather.

Turning off TCS or ESC in the rain would be like removing the safety net that is designed to catch you when you slip. It would significantly increase your risk of losing control, especially if you encounter a patch of standing water or need to make a sudden maneuver.

The only scenario where one might *consider* temporarily disabling TCS or ESC is in deep snow or mud where wheel spin is actually needed to gain momentum. However, this is completely irrelevant to wet weather driving. Always ensure your TCS and ESC are active when driving in the rain.

What are the signs that I might be hydroplaning, and what should I do?

Recognizing the signs of hydroplaning is critical for regaining control. You'll typically notice:

• Sudden Loss of Steering Control: You try to turn the steering wheel, but the car doesn't respond as expected, or it feels unnaturally light.
• Engine RPMs Increase Without Corresponding Acceleration: You press the accelerator, and the engine revs up, but the car doesn't speed up proportionally. This indicates the wheels are spinning on water.
• A "Floating" Sensation: The car might feel like it's floating or gliding, disconnected from the road.
• Visual Cues: You might see a visible spray of water coming from your tires that seems excessive for the current road conditions.

If you suspect you are hydroplaning, here's what you should do:

1. Do NOT Slam on the Brakes: Sudden braking can worsen the loss of control.
2. Do NOT Make Abrupt Steering Inputs: Gentle, smooth steering is key.
3. Ease Off the Accelerator: Gently lift your foot off the gas pedal. This will help the wheels slow down and regain contact with the road.
4. Steer Gently in the Direction You Want to Go: If the car is sliding, make small, smooth adjustments to steer it in the desired direction.
5. Wait for Traction to Return: Once your tires regain contact with the road, you'll feel it. Your steering and acceleration will become responsive again.
6. Once Back in Control, Drive Slowly and Carefully: Reduce your speed and increase your following distance.

Remember, the goal is to avoid sudden inputs that can upset the vehicle's balance on the slippery surface. Patience and gentle corrections are your best tools.

How can I prepare my car for driving in the rain to make it safer?

Preparing your car for rain involves ensuring all its key components are in optimal condition to handle reduced traction and visibility. Here's a checklist:

1. Check Tire Condition:
   • Tread Depth: Ensure your tires have adequate tread depth. Use the penny test or a tread depth gauge. If worn, replace them.
   • Tire Pressure: Inflate tires to the recommended pressure. Incorrect pressure can affect handling and increase hydroplaning risk.
   • Tire Type: Consider tires designed for good wet-weather performance.
2. Inspect Wipers:
   • Blade Condition: Check for cracks, tears, or stiffness in the rubber. Replace them if they streak or skip across the windshield.
   • Wiper Fluid: Ensure your washer fluid reservoir is full.
3. Test Lights:
   • Headlights: Ensure both low and high beams work properly.
   • Taillights and Brake Lights: Verify they are functioning to make you visible.
   • Turn Signals: Crucial for communicating your intentions.
4. Check Brakes:
   • Performance: Listen for any grinding noises or feel for sponginess in the brake pedal. Ensure they are responsive.
   • Fluid Level: Check brake fluid levels if you're comfortable doing so, or have a mechanic inspect them.
5. Inspect Windshield and Windows:
   • Cleanliness: Ensure all glass is free of dirt, smudges, and fog. Apply a water-repellent treatment if possible.
   • De-fogger/Defroster: Verify these systems are working efficiently to clear condensation.
6. Check Other Systems:
   • Traction Control (TCS) and Stability Control (ESC): Ensure these systems are functional.
   • Anti-lock Braking System (ABS): While not something you typically "check" for functionality during maintenance, be aware that ABS is crucial for braking in slippery conditions.
7. Carry an Emergency Kit: While not directly related to rain operation, a basic kit (flares, first-aid, blanket, flashlight) is always advisable.

A well-maintained vehicle, especially with good tires, is your first and best line of defense against the hazards of driving in the rain. It provides the foundation upon which your driving skills can operate safely.

The Future of Cruise Control in the Rain: What to Expect

While the current generation of cruise control systems, even advanced ACC, presents challenges in rainy conditions, the automotive industry is continuously working on improving these technologies. Future iterations of driver-assistance systems, particularly those bordering on semi-autonomous driving, will undoubtedly aim to better handle adverse weather. This might involve:

• More Sophisticated Sensor Fusion: Combining data from multiple sensor types (radar, lidar, cameras, GPS, even weather radar) and using advanced AI to interpret this data more accurately, even when individual sensors are compromised.
• Enhanced Predictive Algorithms: Systems that can better predict the onset of hydroplaning or the reduction in traction based on real-time weather data and road surface analysis.
• Vehicle-to-Everything (V2X) Communication: Cars communicating with each other and with infrastructure (like traffic lights or road sensors) could share real-time information about road conditions, allowing systems to adjust proactively.
• Advanced Tire Technologies: Development of tires that can adapt their grip characteristics to varying road surfaces or provide better real-time feedback on traction levels.

However, even with these advancements, it's highly probable that human oversight and judgment will remain indispensable for safe driving in challenging weather for the foreseeable future. The inherent unpredictability of natural phenomena like rain means that a completely "set it and forget it" experience in all conditions might be a distant dream. For now, the emphasis remains on understanding the limitations of current systems and prioritizing driver responsibility.

In conclusion, the question "Why can't you use cruise control in the rain" boils down to a fundamental conflict between automated speed maintenance and the unpredictable nature of reduced traction. While technology is advancing, the most reliable system for navigating wet roads remains a vigilant, attentive human driver with complete control over their vehicle's acceleration, braking, and steering. Always err on the side of caution, and when in doubt, disengage the cruise control and focus on safe, manual driving.