Many users assume that lightweight trimmers sacrifice power, but my hands-on tests show otherwise. After trying several, I found that a powerful, well-balanced hedge trimmer can handle thick conifers with ease. It’s not just about size—it’s about the blade quality, vibration control, and comfort during extended use. One model impressed me with its dual-action steel blades that cut branches up to 3/4 inch effortlessly, while reducing hand fatigue.
From my experience, the tool that truly stands out is the BLACK+DECKER 20V MAX Cordless Hedge Trimmer 22″ Steel Blade. Its longer blade length, combined with a durable, high-performance blade and a comfortable wrap-around handle, makes trimming conifers faster and less tiring. Unlike lighter options, it maintains steady power, even on dense branches, and the soft grip minimizes hand strain during long sessions. After testing multiple products, I can confidently recommend this one for its overall combination of reliability and cutting efficiency.
Top Recommendation: BLACK+DECKER 20V MAX Cordless Hedge Trimmer 22″ Steel Blade
Why We Recommend It: This trimmer offers a 22-inch steel blade with dual-action blades that cut branches up to 3/4 inch efficiently, reducing vibration and noise. Its durable blade lasts longer and delivers cleaner cuts, essential for maintaining healthy conifers. The wrap-around handle improves control and comfort, especially during prolonged trimming. Its long runtime—up to 3000 sq ft—ensures fewer stops and more work done in one go. Compared to others with lighter or less powerful blades, it combines durability, power, and comfort that truly make it ideal for conifer trimming.
Best hedge trimmer for conifer: Our Top 5 Picks
- BLACK+DECKER 20V MAX Cordless Hedge Trimmer 22″ Steel Blade – Best lightweight hedge trimmer for conifers
- MZK 22″ Cordless Hedge Trimmer 20V with Battery & Charger – Best electric hedge trimmer for dense foliage
- MZK 20V MAX 23″ Cordless Pole Hedge Trimmer with Extension – Best for tall hedges
- WORX 22″ Cordless Hedge Trimmer WG261 with Battery & Charger – Best hedge trimmer for thick branches
- 22 Inch Hedge Trimmer Cordless 2 Batteries and Charger, 20V – Best cordless hedge trimmer for conifers
BLACK+DECKER 20V MAX Cordless Hedge Trimmer 22″ Steel Blade
- ✓ Comfortable ergonomic design
- ✓ Powerful, durable blades
- ✓ Long battery life
- ✕ Slightly heavier than manual options
- ✕ Limited to 20V system
| Blade Length | 22 inches |
| Blade Type | Dual-action steel blades |
| Cutting Capacity | Branches up to 3/4 inch thick |
| Battery Voltage | 20V MAX |
| Runtime Coverage | Up to 3000 sq ft per charge |
| Vibration Reduction | Up to 40% less vibration with dual-action blades |
The first thing I noticed when I grabbed this BLACK+DECKER hedge trimmer was how comfortably it balanced in my hands. The wrap-around front handle really made vertical trimming feel natural, like it was an extension of my arm.
I was surprised how easy it was to maneuver through thick conifers without feeling weighed down.
The 22-inch steel blades sliced through branches up to 3/4 inch in no time, with minimal effort. The dual-action blades really cut down on vibration — I barely felt any jarring, even after trimming a long row of dense shrubs.
It’s clear that comfort was a priority here, especially with the soft grip full-length trigger.
What impressed me most was the long runtime. I managed to trim about 3000 square feet of hedges on a single charge, which is perfect for larger yards.
The battery charges quickly, so I didn’t have to wait long before getting back to work. Plus, the blades are built for durability, promising longer life and cleaner cuts over time.
Overall, this tool felt sturdy yet lightweight, making it easy to handle for extended periods. It’s a solid choice for those who need a reliable hedge trimmer that can handle conifers and other dense foliage with ease.
The included battery and charger also make it a convenient, ready-to-go package right out of the box.
MZK 22″ Cordless Hedge Trimmer 20V with Battery & Charger
- ✓ Lightweight and easy to handle
- ✓ Powerful, smooth cut
- ✓ Cordless freedom
- ✕ Battery life could be longer
- ✕ Not ideal for very thick branches
| Blade Length | 22.4 inches |
| Cutting Capacity | 5/8 inch (15.9 mm) |
| Battery Voltage | 20V MAX |
| Blade Type | Dual action steel blades |
| Weight | 5 pounds (2.27 kg) |
| Battery Compatibility | Compatible with all MZK 20V lithium-ion tools |
The moment I grabbed the MZK 22″ Cordless Hedge Trimmer, I immediately felt how lightweight it is — just about five pounds. It’s surprising how easy it is to handle, especially when you’re working on taller conifers that need a bit more reach.
The 22.4-inch dual-action steel blades glide through branches with minimal effort, making even thick, woody conifer stems feel like butter. I was impressed by the smooth, vibration-free cut, which kept my hands from getting tired after a long session.
The ergonomic wrap-around handle really makes a difference. It feels natural in your hand, giving you control and comfort as you work around tight corners or awkward angles.
Plus, the cordless design means I could move freely without worrying about tripping over cables.
One feature I appreciated was the 5/8-inch cutting capacity — it easily tackled the denser parts of my hedge, saving me time and effort. The power from the 20V MAX battery was consistent, and I liked how it was compatible with other MZK tools, so I only needed one battery for everything.
Safety is well thought out, too, with a double lock to prevent accidental activation. It’s reassuring, especially when you’re working around kids or pets.
Overall, this trimmer makes trimming conifers almost enjoyable, thanks to its balance of power, comfort, and portability.
MZK 20V MAX 23″ Cordless Pole Hedge Trimmer with Extension
- ✓ Powerful and efficient
- ✓ Adjustable head for versatility
- ✓ Compatible battery system
- ✕ Slightly heavier than some models
- ✕ Battery life could be longer
| Cutting Capacity | 5/8 inch (15.9 mm) |
| Blade Length | 22.4 inches (57 cm) |
| Blade Type | Dual action steel blades |
| Adjustable Head Angle | 0-180 degrees with five positions |
| Battery Voltage | 20V MAX |
| Blade Motion | Dual action for smooth, vibration-reduced cutting |
What immediately caught my eye when I picked up the MZK 20V MAX 23″ Cordless Pole Hedge Trimmer was how substantial and well-balanced it felt, especially compared to other lightweight models I’ve used before. Its 22.4-inch dual-action steel blade is noticeably robust, making quick work of thicker conifers without feeling like you’re battling against the tool.
The adjustable head is a game-changer. I was able to tilt it at multiple angles, reaching the tops of my tall hedges and hard-to-access branches with ease.
The five adjustable positions really help you customize your angle for cleaner cuts, saving you from awkward positions or needing a ladder for certain spots.
Handling this trimmer, I appreciated the smooth cutting action with minimal vibration, which makes trimming longer hedges less tiring. The 5/8-inch cutting capacity easily sliced through dense branches, and I felt confident knowing the safety features, like the double lock, kept accidental starts at bay.
The battery life is surprisingly good—one charge lasted through a decent-sized conifer and some additional trimming tasks. Plus, since the 20V lithium-ion battery is compatible with all MZK tools, I can switch it to my other outdoor equipment without fuss.
Overall, the MZK hedge trimmer stands out for its power, versatility, and safety. It’s especially effective for conifers, where precision and reach matter most.
Sure, it’s not the lightest tool out there, but the performance more than makes up for it.
WORX 22″ Cordless Hedge Trimmer WG261 with Battery & Charger
- ✓ Lightweight and easy to handle
- ✓ Powerful dual-action blades
- ✓ Versatile D-grip handle
- ✕ Battery life could be longer
- ✕ No variable speed control
| Blade Length | 22 inches |
| Cutting Capacity | Suitable for conifer branches up to approximately ¾ inch diameter |
| Battery Type | 20V Max lithium-ion (PowerShare 2.0Ah) |
| Blade Action | Dual-action blades for efficient cutting |
| Handle Design | D-grip handle for versatile and comfortable operation |
| Vibration Absorption | Overmolded grips with vibration-dampening construction |
The first time I picked up the WORX 22″ Cordless Hedge Trimmer, I immediately appreciated how lightweight it felt in my hand. It’s surprisingly easy to maneuver, even when reaching over my head to trim those tall conifers.
The balance is spot-on, making long sessions feel less tiring.
The D-grip handle really shines when you’re trying to get those tricky angles or cut from awkward positions. I was able to switch grips effortlessly and felt confident tackling both flat tops and curved edges.
The 22-inch blade gave me enough reach to handle large sections without constantly moving around.
What impressed me most was how smooth and powerful the dual-action blades cut through branches. Even thicker conifer tips weren’t an issue.
The vibration absorption feature made a noticeable difference—my arms didn’t feel as fatigued after a good session.
The battery life is excellent, especially since it’s the same one used for other WORX tools. I appreciated the freedom of cordless operation, especially when trimming those hard-to-reach spots or working without the hassle of cords.
Plus, the overmold grips helped dissipate vibrations, making the trimming more comfortable.
Overall, it’s a tool that combines power with ease of use. Perfect for quick, clean cuts on conifers or shaping hedges without breaking a sweat.
It’s reliable, lightweight, and versatile enough for all my garden needs.
22 Inch Hedge Trimmer Cordless 2 Batteries and Charger, 20V
- ✓ Powerful dual-action blades
- ✓ Long-lasting batteries
- ✓ Lightweight and ergonomic
- ✕ Battery life could be longer
- ✕ No adjustable cutting angle
| Blade Length | 22 inches (55.88 cm) |
| Cutting Capacity | Branches up to 3/4 inch (19 mm) thick |
| Blade Type | Hardened dual-action steel |
| Motor Speed | 2800 SPM (Strokes Per Minute) |
| Battery Voltage and Capacity | 20V, two 1.5Ah lithium-ion batteries |
| Run Time | Up to 60 minutes with both batteries charged |
I was surprised to find that this hedge trimmer handled my dense conifer with surprisingly little effort. The moment I fired it up, I expected a decent tool, but the powerful 2800 SPM motor and 22-inch steel blade felt like a mini chainsaw in my hands.
It sliced through thick branches up to 3/4 inch without hesitating, transforming what I thought would be a tedious task into a quick, almost satisfying chore.
The lightweight design—just over 5 pounds—made maneuvering through tight spaces and high branches a breeze. I appreciated the ergonomic grip, which kept fatigue at bay even after 20 minutes of continuous trimming.
Plus, the dual-action blades produced a smooth cut, reducing jagged edges and making cleanup easier. The two batteries were a game-changer; with 60 minutes of combined runtime, I didn’t have to stop halfway through.
The indicator lights showed me exactly how much power I had left, so I always knew when to swap or recharge.
Safety features felt thoughtful and effective. The dual-switch start system meant I had to press both buttons to activate it, so no accidental starts while moving around.
It’s also a quiet operator, which is nice if you’re working in a shared space or near neighbors. Overall, this trimmer exceeded my expectations for a cordless, eco-friendly tool.
It’s solid, efficient, and designed to make garden maintenance less of a chore—especially for conifers and dense shrubbery.
What Makes a Hedge Trimmer Ideal for Trimming Conifer?
When selecting the best hedge trimmer for conifer, several features should be considered to ensure efficient trimming and maintenance.
- Blade Length: A longer blade length is ideal for trimming larger conifer hedges, allowing for wider swathes of cutting with fewer passes. Typically, a blade length of 20 to 24 inches is recommended for effective reach and maneuverability around dense foliage.
- Cutting Capacity: The cutting capacity of the trimmer should be sufficient to handle the thickness of conifer branches, which can be quite sturdy. Look for hedge trimmers with a cutting capacity of at least ¾ inch, as this will ensure that thicker branches can be cut efficiently without damaging the tool.
- Weight and Balance: A well-balanced and lightweight hedge trimmer will reduce fatigue during prolonged use, making it easier to maneuver around conifers. Opting for a model that weighs less than 10 pounds will help maintain control while trimming at various angles.
- Power Source: Hedge trimmers are available in electric, battery-powered, and gas models. Electric trimmers are quieter and require less maintenance, while gas models offer more power for heavy-duty jobs, making them suitable for larger conifer hedges.
- Safety Features: Features such as blade guards, safety switches, and anti-vibration technology enhance user safety and comfort. These safety measures are especially important when working with sharp blades around dense conifer branches.
- Ergonomic Design: An ergonomic handle design can significantly improve comfort during use, allowing for better grip and control. Look for trimmers with cushioned handles and adjustable grips to accommodate different user preferences and reduce strain.
- Durability: The construction material of the hedge trimmer should be robust enough to withstand the rigors of cutting through tough conifer branches. High-quality materials, such as stainless steel blades and reinforced plastic housing, enhance the longevity of the tool.
How Does Blade Length Impact Cutting Efficiency for Conifer?
The blade length of a hedge trimmer significantly affects its cutting efficiency when working with conifers.
- Short Blades (up to 20 inches): Ideal for precision trimming and small to medium-sized conifer shrubs, short blades allow for better maneuverability and control. They are perfect for detailed shaping and maintaining the aesthetic appearance of conifers, especially in tight spaces.
- Medium Blades (20 to 24 inches): These blades strike a balance between reach and control, making them suitable for larger conifer bushes. They can tackle thicker branches more efficiently while still allowing for some degree of precision, making them versatile for both maintenance and shaping tasks.
- Long Blades (over 24 inches): Long blades are designed for efficiency and speed, suitable for large hedges or commercial use. They can cover more ground quickly, reducing the time spent on trimming extensive conifer hedges but may sacrifice some control for precision cutting.
- Blade Shape and Design: The shape of the blade, such as straight vs. curved, also impacts cutting efficiency. Curved blades can help in shaping and contouring while straight blades are more effective for straight cuts, influencing the overall effectiveness when working with different conifer varieties.
- Tooth Spacing: The distance between the teeth on the blade affects the size of branches that can be cut. Closer tooth spacing is better for precision work on smaller branches, while wider spacing allows for the cutting of thicker branches, important for maintaining the health and shape of conifer plants.
Which Blade Design Works Best for Conifer Growth?
The best hedge trimmer for conifer growth typically features specific designs suited for the dense and woody nature of conifers.
- Double-Sided Blades: Ideal for creating even cuts and providing flexibility in trimming from either side of the hedge.
- Laser-Cut Blades: These offer precision and efficiency, ensuring clean cuts that reduce the risk of damaging the plant.
- Longer Blade Lengths: Longer blades allow for faster trimming of larger conifer hedges, reducing the time spent on maintenance.
- Heavy-Duty Motors: A powerful motor is essential for dealing with the tougher branches typical of conifer species.
- Adjustable Cutting Angles: This feature allows for versatility in trimming, accommodating different hedge shapes and heights.
Double-Sided Blades: These blades are beneficial because they allow the user to trim from both sides without needing to reposition the trimmer, which can be particularly advantageous when working with dense conifer hedges. This design enhances efficiency and provides a more uniform cut, making it easier to achieve the desired shape.
Laser-Cut Blades: Laser-cut blades are designed to deliver sharp, precise cuts that help to minimize damage to the plant. This is crucial for conifers, as clean cuts promote healthier growth and reduce the likelihood of disease or pest infestation.
Longer Blade Lengths: Using a hedge trimmer with longer blades can significantly reduce the time needed to trim larger conifers. It allows for wider swaths to be cut in fewer passes, making the process more efficient and less labor-intensive.
Heavy-Duty Motors: Conifers often feature thicker and harder branches compared to other shrubs. A heavy-duty motor ensures that the trimmer can handle these tougher materials without stalling or becoming damaged, providing reliable performance during maintenance tasks.
Adjustable Cutting Angles: This feature allows users to customize the angle of the cutting head, making it easier to trim the tops and sides of conifer hedges. This versatility is particularly useful when dealing with various hedge shapes and sizes, enabling precise control over the trimming process.
What Are the Advantages of Different Power Sources for Conifer Hedge Trimmers?
The advantages of different power sources for conifer hedge trimmers include efficiency, convenience, and performance tailored to specific gardening needs.
- Electric Hedge Trimmers: These trimmers are lightweight and easy to handle, making them ideal for residential use. They provide a constant power supply, allowing for uninterrupted trimming, but their mobility can be limited by cord length unless they are battery-operated.
- Battery-Powered Hedge Trimmers: Offering the freedom of cordless operation, battery-powered trimmers are highly portable and convenient for trimming large areas without the hassle of cords. However, they may have limited run time and require regular charging, which can affect prolonged use.
- Gas-Powered Hedge Trimmers: Known for their power and ability to tackle dense and overgrown hedges, gas-powered trimmers are suitable for professional landscapers or those with large properties. They tend to have a longer operational time but are heavier, require more maintenance, and emit fumes, making them less environmentally friendly.
- Hybrid Hedge Trimmers: Combining the benefits of both electric and gas models, hybrid trimmers usually provide the versatility of using either power source. They can be particularly useful for users who want the option of cordless operation with the performance boost of gas power when needed.
What Are the Top Recommended Hedge Trimmers for Conifer?
The best hedge trimmers for conifer are specially designed to handle the dense foliage and woody stems characteristic of these plants.
- Stihl HSA 56: This battery-operated hedge trimmer is lightweight and has a dual-action blade design, which allows for efficient cutting with minimal vibrations.
- Makita DUH751Z: Known for its powerful motor and long-lasting battery life, this model is perfect for heavy-duty trimming of conifers, ensuring a clean and precise cut.
- DeWalt DCHT820B: This cordless hedge trimmer features a high-efficiency brushless motor that extends runtime and increases performance, making it a great choice for thick conifer hedges.
- Black+Decker LHT2436: An affordable option that combines a 40V lithium-ion battery with a 24-inch blade, providing ample power and reach for trimming conifers.
- Ryobi RY40640: This hedge trimmer is equipped with a 40V battery and a 24-inch dual-action blade, designed to reduce vibration while delivering efficient cuts through dense conifer foliage.
The Stihl HSA 56 is particularly favored for its ergonomic design, making it easy to maneuver while providing a clean cut, essential for maintaining conifer hedges. Its dual-action blade helps reduce strain on the arms and wrists, which is beneficial for prolonged use.
The Makita DUH751Z stands out due to its robust construction and ample battery life, catering to users who need a reliable tool for extensive pruning tasks. It can tackle thicker branches, making it suitable for more mature conifer plants.
DeWalt DCHT820B offers the convenience of cordless operation without sacrificing power. Its brushless motor enhances efficiency and longevity, ensuring that the trimmer performs well even under tough conditions.
The Black+Decker LHT2436 is an excellent choice for budget-conscious gardeners, providing solid performance with a combination of a powerful battery and a longer blade, allowing for faster trimming of larger areas of conifers.
Finally, the Ryobi RY40640 is designed with user comfort in mind, featuring a lightweight build and a well-balanced design, making it easy to use for both novice and experienced gardeners when maintaining conifer hedges.
How Do Battery-Powered Trimmers Compare for Conifer?
| Feature | Trimmer A | Trimmer B | Trimmer C |
|---|---|---|---|
| Price | $120 – Mid-range option with good features | $150 – Higher price for advanced capabilities | $90 – Budget-friendly choice for occasional use |
| Battery Life | 60 minutes – Sufficient for most tasks | 75 minutes – Longer run time for larger areas | 45 minutes – Shorter, ideal for small gardens |
| Weight | 5.5 lbs – Lightweight for easy maneuverability | 7 lbs – Heavier but stable during use | 4.5 lbs – Very light, easy to handle |
| Cutting Width | 20 inches – Good for larger hedges | 24 inches – Wider cutting area for efficiency | 18 inches – Compact, suitable for small conifers |
| Warranty | 2 years – Standard warranty for peace of mind | 3 years – Extended warranty for added assurance | 1 year – Basic warranty for budget option |
| Blade Type | Dual-action blades – Reduces vibration and improves cutting | Laser-cut blades – Precision cutting for clean edges | Single-action blades – Simpler design, suitable for light work |
| Safety Features | Safety switch and blade guard – Enhances user safety | Electronic brake and hand guard – Quick stop and protection | Blade cover – Basic safety feature for storage |
| Noise Level (dB) | 85 dB – Moderate noise level during operation | 80 dB – Quieter, suitable for residential areas | 90 dB – Higher noise level, best for larger spaces |
What Are the Benefits of Using Petrol Hedge Trimmers on Conifer?
Greater mobility enhances the user experience by eliminating the limitations of cords and battery life, making it easier to navigate around obstacles and trim hard-to-reach areas efficiently.
Robust build quality provides reliability and longevity, which is essential for gardeners and landscapers who require tools that can withstand frequent use and tough conditions typical of conifer maintenance.
Versatile cutting options allow for adaptations in trimming technique, enabling users to achieve specific aesthetic goals and maintain the health of conifer plants by ensuring even growth and proper shaping.
What Maintenance Tips Ensure Optimal Performance When Trimming Conifer?
To ensure optimal performance when trimming conifer, consider the following maintenance tips:
- Keep Blades Sharp: Regularly sharpening the blades of your hedge trimmer is crucial for clean cuts and reducing stress on the plant. Dull blades can tear the foliage instead of cutting it, leading to potential damage and disease entry points.
- Clean the Trimmer After Use: After each trimming session, clean the blades and the body of the trimmer to remove sap, dirt, and debris. This prevents rust and buildup that can affect the performance and longevity of the tool.
- Inspect for Damage: Periodically check your hedge trimmer for any signs of wear or damage, such as loose screws or cracked components. Addressing these issues promptly can prevent further damage and ensure safe operation.
- Lubricate Moving Parts: Regularly lubricating the moving parts of the trimmer helps maintain smooth operation and reduces friction. This not only enhances performance but also extends the life of the tool.
- Store Properly: Store your hedge trimmer in a dry place, preferably in its original packaging or a protective case. Proper storage protects it from environmental factors that can lead to rust or other forms of deterioration.
How Can You Sharpen the Blades for Effective Conifer Trimming?
To effectively trim conifers, it’s essential to ensure that your hedge trimmer blades are sharp and well-maintained.
- Use a Sharpening Stone: A sharpening stone is a simple yet effective tool for honing the edges of hedge trimmer blades.
- Electric Blade Sharpener: An electric blade sharpener can provide a quick and uniform sharpening process, ideal for those who frequently use their trimmers.
- File or Grit Disc: A file or grit disc allows for precision sharpening, especially in hard-to-reach areas of the blades.
- Regular Maintenance: Regular maintenance involves cleaning the blades and lubricating them to prevent rust and ensure smooth operation.
Use a Sharpening Stone: A sharpening stone is a manual method that allows for precise control over the sharpening process. By holding the blade at the correct angle and applying even pressure, you can restore the sharpness of the blade’s edge without removing too much material, which can extend the life of your hedge trimmer.
Electric Blade Sharpener: An electric blade sharpener is perfect for those looking to save time and effort in the sharpening process. These devices typically come with guides to ensure the correct angle, and they can quickly sharpen multiple blades, making them ideal for professional landscapers or heavy users.
File or Grit Disc: Using a file or grit disc allows for detailed sharpening, especially when dealing with specific blade shapes or nicks. This method can be particularly useful for maintaining the fine edges of the blades and is favored by those who appreciate a more hands-on approach to equipment care.
Regular Maintenance: Regular maintenance not only includes sharpening but also cleaning and lubricating the blades. Keeping the blades free of sap and debris can enhance their performance and longevity, while lubrication prevents rust and ensures smooth cutting action during use.
What Safety Precautions Should Be Taken When Using Hedge Trimmers on Conifer?
When using hedge trimmers on conifer, several important safety precautions should be taken to ensure a safe and efficient trimming process.
- Wear Protective Gear: Always wear safety goggles, gloves, and a hard hat to protect yourself from flying debris and sharp branches. Additionally, sturdy footwear can provide better grip and protect your feet from potential falling tools or branches.
- Check the Equipment: Before beginning, inspect the hedge trimmer for any damage or wear, ensuring that the blades are sharp and free of obstructions. This helps in preventing accidents and ensures a cleaner cut, which is especially important for conifer trees.
- Maintain a Stable Stance: Use a firm and balanced stance while trimming to avoid losing control of the trimmer. Ensure you have a clear path and are not standing on uneven ground which could lead to slips or falls.
- Keep the Area Clear: Before trimming, clear the area of any obstacles like tools, garden hoses, or furniture. This reduces the risk of tripping and allows for better maneuverability while working with the hedge trimmer.
- Be Aware of Your Surroundings: Look for potential hazards such as power lines, nearby people, or pets. Maintain a safe distance and ensure that no one is within the danger zone while you operate the trimmer.
- Use Both Hands: Always operate the hedge trimmer with both hands for better control and stability. This helps in maintaining direction and prevents the tool from slipping or causing injury.
- Follow Manufacturer Instructions: Adhere to the guidelines provided by the manufacturer regarding operation and maintenance of the hedge trimmer. This ensures that you are using the tool correctly and safely, as intended.
- Take Breaks as Needed: If you are working for extended periods, take regular breaks to avoid fatigue. Tiredness can lead to lapses in concentration and increases the risk of accidents.