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84-465: The term "driver" originated in the 15th century, referring to the occupation of driving working animals such as pack or draft horses . It later applied to electric railway drivers in 1889 and motor-car drivers in 1896. The world's first long-distance road trip by automobile was in 1888, when Bertha Benz drove a Benz Patent-Motorwagen from Mannheim to Pforzheim , Germany. Driving requires both physical and mental skills, as well as an understanding of

168-843: A certificate that proves the vehicle is safe and roadworthy . Also, it needs to have a minimum of third party insurance . Drivers may be required to take lessons with an approved driving instructor (or are strongly encouraged to do so) and must pass a driving test before being granted a license. Almost all countries allow all adults with good vision and health to apply to take a driving test and, if successful, to drive on public roads. In many countries, even after passing one's driving test, new drivers are initially subject to special restrictions under graduated driver licensing rules. For example, in Australia, novice drivers are required to carry "P" ("provisional") plates, while in New Zealand it

252-533: A locomobile , to the summit of Mount Washington in New Hampshire in the United States to generate publicity for their automobile. The 7.6-mile (12.2 km) journey took over two hours (not counting time to add more water); the descent was accomplished by putting the engine in low gear and much braking. Driving in traffic is more than just knowing how to operate the mechanisms which control

336-506: A day. Overfeeding can lead to obesity, and risk of laminitis can be a concern. The largest horse in recorded history was probably a Shire born in 1846 named Sampson (renamed Mammoth). He stood 218  cm (21.2 hands) high, and his peak weight was estimated at 1,524 kilograms (3,360 lb). At over 193  cm (19 hands), a Shire gelding named Goliath (1977–2001) was the Guinness Book of World Records record holder for

420-491: A docile temperament. While indispensable to generations of pre-industrial farmers, draft horses are used today for a multitude of purposes, including farming, draft horse showing , logging, recreation, and other uses. Draft breeds have been crossbred with light riding breeds such as the Thoroughbred to create sport horses or warmbloods . While most draft horses are used for driving , they can be ridden and some of

504-606: A driver's mental skills. Safety concerns in driving include poor road conditions, low visibility, texting while driving , speeding , impaired driving , sleep-deprived driving , and reckless driving . Laws regarding driving, driver licensing , and vehicle registration vary between jurisdictions. Most countries have laws against driving under the influence of alcohol or other drugs. Some countries impose annual renewals or point systems for driver's licenses to maintain road safety. The World Health Organization estimates that 1.35 million people are killed each year in road traffic; it

588-762: A jump effectively as well as absorb small bumps along the off-road terrain effectively. The severe handling vice of the TR3B and related cars was caused by running out of suspension travel. Other vehicles will run out of suspension travel with some combination of bumps and turns, with similarly catastrophic effect. Excessively modified cars also may encounter this problem. In general, softer rubber , higher hysteresis rubber and stiffer cord configurations increase road holding and improve handling. On most types of poor surfaces, large diameter wheels perform better than lower wider wheels. The depth of tread remaining greatly affects aquaplaning (riding over deep water without reaching

672-428: A live axle does, but represents an improvement because the differential is mounted to the body, thereby reducing the unsprung weight.) Wheel materials and sizes will also have an effect. Aluminium alloy wheels are common due to their weight characteristics which help to reduce unsprung mass. Magnesium alloy wheels are even lighter but corrode easily. Since only the brakes on the driving wheels can easily be inboard,

756-445: A longer car to turn with a given radius. Power steering reduces the required force at the expense of feel. It is useful, mostly in parking, when the weight of a front-heavy vehicle exceeds about ten or fifteen times the driver's weight, for physically impaired drivers and when there is much friction in the steering mechanism. Four-wheel steering has begun to be used on road cars (Some WW II reconnaissance vehicles had it). It relieves

840-404: A million draft horses were used during World War I . The British were importing American draft horses to supplement their dwindling stock even before America joined the war, preferring Percheron crosses which they said had "great endurance, fine physique, soundness, activity, willingness to work, and almost unfailing good temper". British buyers were buying 10,000 to 25,000 American horses and mules

924-524: A month, eventually making up about two-thirds of British Army war horses. In the late 19th century and early 20th century, thousands of draft horses were imported from Western Europe into the United States . Percherons came from France, Belgians from Brabant , Shires from England, Clydesdales from Scotland. Many American draft breed registries were founded in the late 19th century. The Percheron, with 40,000 broodmares registered as of 1915,

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1008-399: A more rearward weight distribution. In the case of pure racing cars, this is typically between "40/60" and "35/65". This gives the front tires an advantage in overcoming the car's moment of inertia (yaw angular inertia), thus reducing corner-entry understeer. Using wheels and tires of different sizes (proportional to the weight carried by each end) is a lever automakers can use to fine tune

1092-412: A source of horsepower for farming, hauling freight and moving passengers. The advent of railroads increased demand for working horses, as a growing economy still needed transport over the 'last mile' between the goods yard or station and the final customer. Even in the 20th century, until motor vehicles became an affordable and reliable substitute, draft horses were used for practical work. Over half

1176-547: A tight-radius (lower speed) corner the angular velocity of the car is high, while in a longer-radius (higher speed) corner the angular velocity is much lower. Therefore, the front tires have a more difficult time overcoming the car's moment of inertia during corner entry at low speed, and much less difficulty as the cornering speed increases. So the natural tendency of any car is to understeer on entry to low-speed corners and oversteer on entry to high-speed corners. To compensate for this unavoidable effect, car designers often bias

1260-585: A traumatic brain injury). Some jurisdictions implement road space rationing , where vehicles are banned from driving on certain days depending on a variety of criteria, most commonly the letters and digits in their vehicle registration plate . A few countries banned women driving in the past. In Oman , women were not allowed to drive until 1970. In Saudi Arabia , women were not issued driving licenses until 2018. Saudi women had periodically staged driving protests against these restrictions and in September 2017,

1344-413: A turn of the steering wheel and the rear wheels have a smaller slip angle than the front wheels. However this may not be achievable for all loading, road and weather conditions, speed ranges, or while turning under acceleration or braking. Ideally, a car should carry passengers and baggage near its center of gravity and have similar tire loading, camber angle and roll stiffness in front and back to minimise

1428-456: A variety of duties. One type of horse-powered work was the hauling of heavy loads, plowing fields, and other tasks that required pulling ability. A heavy, calm, patient, and well-muscled animal was desired for this work. Conversely, a light, more energetic horse was needed for riding and rapid transport. Thus, to the extent possible, a certain amount of selective breeding was used to develop different types of horse for different types of work. It

1512-431: A vehicle's "active" safety. They also affect its ability to perform in auto racing . The maximum lateral acceleration is, along with braking, regarded as a vehicle’s road holding ability. Automobiles driven on public roads whose engineering requirements emphasize handling over comfort and passenger space are called sports cars . The centre of mass height, also known as the centre of gravity height, or CGZ, relative to

1596-536: Is a bit slower than lighter horse breeds, more akin to that of ponies, requiring less feed per pound of body weight. This is possibly due to their calmer nature. Nonetheless, because of their sheer size, most require a significant amount of feed per day. Generally a supplement to balance nutrients is preferred over a large quantity of grain. They consume hay or other forage from 1.5% to 3% of their body weight per day, depending on work level. They also can drink up to 95 litres; 21 imperial gallons (25 US gal) of water

1680-683: Is a common misunderstanding that the Destrier that carried the armoured knight of the Middle Ages had the size and conformation of a modern draft horse, and some of these Medieval war horses may have provided some bloodlines for some of the modern draft breeds. The reality was that the high-spirited, quick-moving Destrier was closer to the size, build, and temperament of a modern Andalusian or Friesian . There also were horses of more phlegmatic temperaments used for pulling military wagons or performing ordinary farm work which provided bloodlines of

1764-539: Is a computerized technology that improves the safety of a vehicle's stability by attempting to detect and prevent skids. When ESC detects loss of steering control, the system applies individual brakes to help "steer" the vehicle where the driver wants to go. Braking is automatically applied to individual wheels, such as the outer front wheel to counter oversteer, or the inner rear wheel to counter understeer. The stability control of some cars may not be compatible with some driving techniques, such as power induced over-steer. It

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1848-403: Is a high rate of injury and death caused by motor vehicle accidents that involve teenage drivers. There is evidence that the less teenagers drive, the risk of injury drops. There is a lack of evidence as to whether educational interventions to promote active transport and share information about the risks, cost, and stresses involved with driving are effective at reducing or delaying car driving in

1932-406: Is also a handling characteristic. Ignoring the flexing of other components, a car can be modeled as the sprung weight, carried by the springs, carried by the unsprung weight , carried by the tires, carried by the road. Unsprung weight is more properly regarded as a mass which has its own inherent inertia separate from the rest of the vehicle. When a wheel is pushed upwards by a bump in the road,

2016-409: Is called restricted (R). Many U.S. states now issue graduated drivers' licenses to novice minors. While graduated driver licensing rules vary between jurisdictions, typical restrictions include newly licensed minors not being permitted to drive or operate a motorized vehicle at night or with a passenger other than family members, zero blood alcohol, and limited power-to-weight ratio of the vehicle. It

2100-448: Is complicated by load transfer , which is proportional to the (negative) acceleration times the ratio of the center of gravity height to the wheelbase. The difficulty is that the acceleration at the limit of adhesion depends on the road surface, so with the same ratio of front to back braking force, a car will understeer under braking on slick surfaces and oversteer under hard braking on solid surfaces. Most modern cars combat this by varying

2184-560: Is considered to help handling. At least it simplifies the suspension engineers work. Some cars, such as the Mercedes-Benz 300SL have had high door sills to allow a stiffer frame. Handling is a property of the car, but different characteristics will work well with different drivers. The more experience a person has with a car or type of car the more likely they will be to take full advantage of its handling characteristics under adverse conditions. Weather affects handling by changing

2268-427: Is large enough, the wheel may be temporarily separated from the road surface before it has descended back into contact with the road surface. This unsprung weight is cushioned from uneven road surfaces only by the compressive resilience of the tire (and wire wheels if fitted), which aids the wheel in remaining in contact with the road surface when the wheel inertia prevents close-following of the ground surface. However,

2352-506: Is not a concern. A linear spring will behave the same at all times. This provides predictable handling characteristics during high speed cornering, acceleration and braking. Variable springs have low initial springs rates. The spring rate gradually increases as it is compressed. In simple terms the spring becomes stiffer as it is compressed. The ends of the spring are wound tighter to produce a lower spring rate. When driving this cushions small road imperfections improving ride quality. However once

2436-423: Is possible for a driver to be suspended or disqualified (banned) from driving, either for a short time or permanently. This is usually in response to a serious traffic offence (for example, causing death due to drink driving), repeated minor traffic offences (for example, accruing too many demerit points for speeding), or for a specific medical condition which prevents driving, pending a future assessment (for example,

2520-476: Is prominent on many types of racing cars, but is also used on most passenger cars to some degree, if only to counteract the tendency for the car to otherwise produce positive lift. In addition to providing increased adhesion, car aerodynamics are frequently designed to compensate for the inherent increase in oversteer as cornering speed increases. When a car corners, it must rotate about its vertical axis as well as translate its center of mass in an arc. However, in

2604-412: Is that power induced oversteer is useful to a skilled driver for tight curves. The weight transfer under acceleration has the opposite effect and either may dominate, depending on the conditions. Inducing oversteer by applying power in a front wheel drive car is possible via proper use of " left-foot braking ”, and using low gears down steep hills may cause some oversteer. The effect of braking on handling

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2688-623: Is the leading cause of death for people age 5 to 29. The origin of the term driver , as recorded from the 15th century, refers to the occupation of driving working animals , especially pack horses or draft horses . The verb to drive in origin means "to force to move, to impel by physical force". It is first recorded of electric railway drivers in 1889 and of a motor-car driver in 1896. Early alternatives were motorneer , motor-man , motor-driver or motorist . French favors " conducteur " (the English equivalent, " conductor ", being used—from

2772-481: Is therefore, at least from a sporting point of view, preferable that it can be disabled. Of course things should be the same, left and right, for road cars. Camber affects steering because a tire generates a force towards the side that the top is leaning towards. This is called camber thrust. Additional front negative camber is used to improve the cornering ability of cars with insufficient camber gain. The frame may flex with load, especially twisting on bumps. Rigidity

2856-596: The Amish and Mennonites . Draft horses are still used for logging , a forestry management practice to remove logs from dense woodland where there is insufficient space for mechanized vehicles or for other conservation considerations. Draft horse breeds have played a significant role in the development of many warmblood breeds, popular today in advanced level equine sports. Small areas still exist where draft horses are widely used as transportation due to legislation preventing automotive traffic, such as on Mackinac Island in

2940-499: The Citroën 2CV had inertial dampers on its rear wheel hubs to damp only wheel bounce. Aerodynamic forces are generally proportional to the square of the air speed, therefore car aerodynamics become rapidly more important as speed increases. Like darts, airplanes, etc., cars can be stabilised by fins and other rear aerodynamic devices. However, in addition to this cars also use downforce or "negative lift" to improve road holding. This

3024-507: The Vienna Convention on Road Signs and Signals standardises road signs, traffic lights and road markings to improve safety. The rules of the road, driver licensing and vehicle registration schemes vary considerably between jurisdictions, as do laws imposing criminal responsibility for negligent driving , vehicle safety inspections and compulsory insurance . Most countries also have differing laws against driving while under

3108-471: The influence of alcohol or other drugs . Aggressive driving and road rage have become problems for drivers in some areas. Some countries require annual renewal of the driver's license. This may require getting through another driving test or vision screening test to get recertified. Also, some countries use a points system for the driver's license. Both techniques (annual renewal with tests, points system) may or may not improve road safety compared to when

3192-496: The rules of the road . Driving over a long distance is referred to as a road trip . In many countries, knowledge of the rules of the road, both practical and theoretical, is assessed with a driving test(s), and those who pass are issued with a driving license . A driver must have physical skills to be able to control direction, acceleration, and deceleration. For motor vehicles, the detailed tasks include: Avoiding or successfully handling an emergency driving situation can involve

3276-490: The tractor , reduced the need for the draft horse. Many were sold to slaughter for horse meat and a number of breeds went into significant decline. Today, draft horses can be seen in horse shows , pulling competitions , heavy horse trials, parades pulling large wagons , and pulling tourist carriages. However, they are still seen on some smaller farms in the US and Europe. They are particularly popular with agrarian groups such as

3360-449: The "wheel bounce" due to wheel inertia, or resonant motion of the unsprung weight moving up and down on the springiness of the tire, is only poorly damped, mainly by the dampers or shock absorbers of the suspension. For these reasons, high unsprung weight reduces road holding and increases unpredictable changes in direction on rough surfaces (as well as degrading ride comfort and increasing mechanical loads). This unsprung weight includes

3444-422: The 1830s—not of the driver but of the person in charge of passengers and collecting fares), while German influenced areas adopted Fahrer (used of coach-drivers in the 18th century, but shortened about 1900 from the compound Kraftwagenfahrer ), and the verbs führen , lenken , steuern —all with a meaning "steer, guide, navigate"—translating to conduire . The world's first long-distance road trip by automobile

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3528-564: The Saudi government agreed to lift the ban, which went into effect in June 2018. Draft horses A draft horse (US) or draught horse (UK), also known as dray horse , carthorse , work horse or heavy horse , is a large horse bred to be a working animal hauling freight and doing heavy agricultural tasks such as plowing . There are a number of breeds, with varying characteristics, but all share common traits of strength, patience, and

3612-550: The United States. Management of a large draft horse can be costly, including feed, shoeing, and veterinary care. Although many draft horses can work without a need for shoes, if they are required, farriers may charge twice the price to shoe a draft horse as a light riding horse because of the extra labor and specialized equipment required. Historically, draft horses were shod with horseshoes that were significantly wider and heavier than those for other types of horses, custom-made, often with caulkins . The draft horse's metabolism

3696-401: The ability of the suspension to keep front and back tire loadings constant on uneven surfaces and therefore contributes to bump steer. Angular inertia is an integral over the square of the distance from the center of gravity, so it favors small cars even though the lever arms (wheelbase and track) also increase with scale. (Since cars have reasonable symmetrical shapes, the off-diagonal terms of

3780-419: The amount of available traction on a surface. Different tires do best in different weather. Deep water is an exception to the rule that wider tires improve road holding. Cars with relatively soft suspension and with low unsprung weight are least affected by uneven surfaces, while on flat smooth surfaces the stiffer the better. Unexpected water, ice, oil, etc. are hazards. When any wheel leaves contact with

3864-451: The angular inertia tensor can usually be ignored.) Mass near the ends of a car can be avoided, without re-designing it to be shorter, by the use of light materials for bumpers and fenders or by deleting them entirely. If most of the weight is in the middle of the car then the vehicle will be easier to spin, and therefore will react quicker to a turn. Automobile suspensions have many variable characteristics, which are generally different in

3948-439: The car's centre of mass into the turn, also generate a torque about the car's vertical axis that starts the car rotating into the turn. However, the lateral force being generated by the rear tires is acting in the opposite torsional sense, trying to rotate the car out of the turn. For this reason, a car with "50/50" weight distribution will understeer on initial corner entry. To avoid this problem, sports and racing cars often have

4032-416: The car's design digitally then "test" that design on the computer. The coefficient of friction of rubber on the road limits the magnitude of the vector sum of the transverse and longitudinal force. So the driven wheels or those supplying the most braking tend to slip sideways. This phenomenon is often explained by use of the circle of forces model. One reason that sports cars are usually rear wheel drive

4116-642: The car's handling toward less corner-entry understeer (such as by lowering the front roll center ), and add rearward bias to the aerodynamic downforce to compensate in higher-speed corners. The rearward aerodynamic bias may be achieved by an airfoil or "spoiler" mounted near the rear of the car, but a useful effect can also be achieved by careful shaping of the body as a whole, particularly the aft areas. In recent years, aerodynamics have become an area of increasing focus by racing teams as well as car manufacturers. Advanced tools such as wind tunnels and computational fluid dynamics (CFD) have allowed engineers to optimize

4200-439: The compressive resilience of the tire results in rolling resistance which requires additional kinetic energy to overcome, and the rolling resistance is expended in the tire as heat due to the flexing of the rubber and steel bands in the sidewalls of the tires. To reduce rolling resistance for improved fuel economy and to avoid overheating and failure of tires at high speed, tires are designed to have limited internal damping. So

4284-433: The distribution of braking in some way. This is important with a high center of gravity, but it is also done on low center of gravity cars, from which a higher level of performance is expected. Depending on the driver, steering force and transmission of road forces back to the steering wheel and the steering ratio of turns of the steering wheel to turns of the road wheels affect control and awareness. Play—free rotation of

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4368-519: The driver is not continuously or annually evaluated. Car ownership does not require a driver's license at all. As such, even with a withdrawn driver's license , former drivers are still legally allowed to possess a car and thus have access to it. In the USA, between 1993 and 1997 13.8% of all drivers involved in fatal crashes had no driver's license. In some countries (such as the UK), the car itself needs have

4452-499: The effect of angular inertia by starting the whole car moving before it rotates toward the desired direction. It can also be used, in the other direction, to reduce the turning radius. Some cars will do one or the other, depending on the speed. Steering geometry changes due to bumps in the road may cause the front wheels to steer in different directions together or independent of each other. The steering linkage should be designed to minimize this effect. Electronic stability control (ESC)

4536-506: The effect on over/under steer is opposite to that of an actual change in the centre of mass. When a car is braking, the downward load on the front tires increases and that on the rear decreases, with corresponding change in their ability to take sideways load. A lower centre of mass is a principal performance advantage of sports cars , compared to sedans and (especially) SUVs . Some cars have body panels made of lightweight materials partly for this reason. Body lean can also be controlled by

4620-490: The following skills: Distractions can compromise a driver's mental skills, as can any altered state of consciousness . One study on the subject of mobile phones and driving safety concluded that, after controlling for driving difficulty and time on task, drivers talking on a phone exhibited greater impairment than drivers who were suffering from alcohol intoxication. In the US "During daylight hours, approximately 481,000 drivers are using cell phones while driving according to

4704-405: The form of body lean. In extreme circumstances, the vehicle may roll over . Height of the centre of mass relative to the wheelbase determines load transfer between front and rear. The car's momentum acts at its centre of mass to tilt the car forward or backward, respectively during braking and acceleration. Since it is only the downward force that changes and not the location of the centre of mass,

4788-449: The front and rear and all of which affect handling. Some of these are: spring rate , damping, straight ahead camber angle , camber change with wheel travel, roll center height and the flexibility and vibration modes of the suspension elements. Suspension also affects unsprung weight . Many cars have suspension that connects the wheels on the two sides, either by a sway bar and/or by a solid axle. The Citroën 2CV has interaction between

4872-416: The front and rear suspension. The flexing of the frame interacts with the suspension. The following types of springs are commonly used for automobile suspension, variable rate springs and linear rate springs. When a load is applied to a linear rate spring the spring compresses an amount directly proportional to the load applied. This type of spring is commonly used in road racing applications when ride quality

4956-517: The handling characteristics of vehicles. Advanced wind tunnels such as Wind Shear's Full Scale, Rolling Road, Automotive Wind Tunnel recently built in Concord, North Carolina have taken the simulation of on-road conditions to the ultimate level of accuracy and repeatability under very controlled conditions. CFD has similarly been used as a tool to simulate aerodynamic conditions but through the use of extremely advanced computers and software to duplicate

5040-432: The hands of an expert driver a neutrally balanced mid-engine car can corner faster, but a FR (front-engined, rear-wheel drive) layout car is easier to drive at the limit. The rearward weight bias preferred by sports and racing cars results from handling effects during the transition from straight-ahead to cornering. During corner entry the front tires, in addition to generating part of the lateral force required to accelerate

5124-415: The inertia of the wheel will cause it to be carried further upward above the height of the bump. If the force of the push is sufficiently large, the inertia of the wheel will cause the tire to completely lift off the road surface resulting in a loss of traction and control. Similarly when crossing into a sudden ground depression, the inertia of the wheel slows the rate at which it descends. If the wheel inertia

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5208-626: The lighter draft breeds are capable performers under saddle. Draft horses are recognizable by their extremely muscular build. They tend to have broad, short backs with powerful hindquarters. In general, they are taller and tend to have heavier bone and a more upright shoulder than riding horses, producing conformation that is well suited for pulling. Many draft breeds have heavier hair, called feathering on their lower legs. Draft breeds range from approximately 163 to 193  cm (16 to 19 hands) high and from 640 to 910 kg (1,400 to 2,000 lb). Humans domesticated horses and used them to perform

5292-461: The modern draft horse. Records indicate that even medieval drafts were not as large as those today. Of the modern draft breeds, the Percheron probably has the closest ties to the medieval war horse. By the 19th century horses weighing more than 730 kilograms (1,600 lb) that also moved at a quick pace were in demand. Tall stature, muscular backs, and powerful hindquarters made the draft horse

5376-590: The publication on the National Highway Traffic Safety Association. Another survey indicated that music could adversely affect a driver's concentration." Seizure disorders and Alzheimer's disease are among the leading medical causes of mental impairment among drivers in the United States and Europe. Whether or not physicians should be allowed, or even required, to report such conditions to state authorities, remains highly controversial. Safety issues in driving include: There

5460-413: The resistance to lateral weight transfer and body lean. The wheelbase provides resistance to longitudinal weight transfer and to pitch angular inertia, and provides the torque lever arm to rotate the car when swerving. The wheelbase, however, is less important than angular inertia (polar moment) to the vehicle's ability to swerve quickly. The wheelbase contributes to the vehicle's turning radius , which

5544-681: The resulting over/understeer characteristics. This increases the time it takes to settle down and follow the steering. It depends on the (square of the) height and width, and (for a uniform mass distribution) can be approximately calculated by the equation: I = M ( h e i g h t 2 + w i d t h 2 ) / 12 {\displaystyle I=M(height^{2}+width^{2})/12} . Greater width, then, though it counteracts center of gravity height, hurts handling by increasing angular inertia. Some high performance cars have light materials in their fenders and roofs partly for this reason Unless

5628-498: The road surface). Increasing tire pressures reduces their slip angle , but lessening the contact area is detrimental in usual surface conditions and should be used with caution. The amount a tire meets the road is an equation between the weight of the car and the type (and size) of its tire. A 1000 kg car can depress a 185/65/15 tire more than a 215/45/15 tire longitudinally thus having better linear grip and better braking distance not to mention better aquaplaning performance, while

5712-417: The road there is a change in handling, so the suspension should keep all four (or three) wheels on the road in spite of hard cornering, swerving and bumps in the road. It is very important for handling, as well as other reasons, not to run out of suspension travel and "bottom" or "top". It is usually most desirable to have the car adjusted for a small amount of understeer , so that it responds predictably to

5796-500: The rules of the road. In many countries, drivers must pass practical and theoretical driving tests to obtain a driving license. Physical skills required for driving include proper hand placement, gear shifting, pedal operation, steering , braking , and operation of ancillary devices. Mental skills involve hazard awareness, decision-making, evasive maneuvering, and understanding vehicle dynamics . Distractions , altered states of consciousness , and certain medical conditions can impair

5880-402: The spring is compressed to a certain point the spring is not wound as tight providing a higher (stiffer) spring rate. This prevents excessive suspension compression and prevents dangerous body roll, which could lead to a roll over. Variable rate springs are used in cars designed for comfort as well as off-road racing vehicles. In off-road racing they allow a vehicle to absorb the violent shock from

5964-444: The springs, anti-roll bars or the roll center heights. In steady-state cornering, front-heavy cars tend to understeer and rear-heavy cars to oversteer (Understeer & Oversteer explained) , all other things being equal. The mid-engine design seeks to achieve the ideal center of mass, though front-engine design has the advantage of permitting a more practical engine-passenger-baggage layout. All other parameters being equal, at

6048-458: The steering is particularly important on ice or hard packed snow where the slip angle at the limit of adhesion is smaller than on dry roads. The steering effort depends on the downward force on the steering tires and on the radius of the contact patch. So for constant tire pressure, it goes like the 1.5 power of the vehicle's weight. The driver's ability to exert torque on the wheel scales similarly with his size. The wheels must be rotated farther on

6132-400: The steering wheel before the wheels rotate—is a common problem, especially in older model and worn cars. Another is friction. Rack and pinion steering is generally considered the best type of mechanism for control effectiveness. The linkage also contributes play and friction. Caster—offset of the steering axis from the contact patch —provides some of the self-centering tendency. Precision of

6216-514: The teenage years. Driveability of a vehicle means the smooth delivery of power, as demanded by the driver. Typical causes of driveability degradation are rough idling , misfiring , surging , hesitation , or insufficient power. Drivers are subject to the laws of the jurisdiction in which they are driving. Some jurisdictions submit to some or all of the requirements of the Geneva Convention on Road Traffic of 1949. Additionally,

6300-407: The track, determines load transfer (related to, but not exactly weight transfer ) from side to side and causes body lean. When tires of a vehicle provide a centripetal force to pull it around a turn, the momentum of the vehicle actuates load transfer in a direction going from the vehicle's current position to a point on a path tangent to the vehicle's path. This load transfer presents itself in

6384-431: The variation in handling characteristics. A driver can learn to deal with excessive oversteer or understeer, but not if it varies greatly in a short period of time. The most important common handling failings are; Ride quality and handling have always been a compromise - technology has over time allowed automakers to combine more of both features in the same vehicle. High levels of comfort are difficult to reconcile with

6468-431: The vehicle is very short, compared to its height or width, these are about equal. Angular inertia determines the rotational inertia of an object for a given rate of rotation. The yaw angular inertia tends to keep the direction the car is pointing changing at a constant rate. This makes it slower to swerve or go into a tight curve, and it also makes it slower to turn straight again. The pitch angular inertia detracts from

6552-421: The vehicle; it requires knowing how to apply the rules of the road (which ensure safe and efficient sharing with other users). An effective driver also has an intuitive understanding of the basics of vehicle handling and can drive responsibly. Although direct operation of a bicycle and a mounted animal are commonly referred to as riding , such operators are legally considered drivers and are required to obey

6636-400: The way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road . It is commonly judged by how a vehicle performs particularly during cornering , acceleration, and braking as well as on the vehicle's directional stability when moving in steady state condition. In the automotive industry , handling and braking are the major components of

6720-406: The wheels and tires, usually the brakes , plus some percentage of the suspension, depending on how much of the suspension moves with the body and how much with the wheels; for instance a solid axle suspension is completely unsprung. The main factors that improve unsprung weight are a sprung differential (as opposed to live axle ) and inboard brakes . (The De Dion tube suspension operates much as

6804-473: The wider tires have better (dry) cornering resistance. The contemporary chemical make-up of tires is dependent of the ambient and road temperatures. Ideally a tire should be soft enough to conform to the road surface (thus having good grip), but be hard enough to last for enough duration (distance) to be economically feasible. It is usually a good idea having different set of summer and winter tires for climates having these temperatures. The axle track provides

6888-425: The world's tallest living horse (until his death). Big Jake (2001–2021), an American Belgian standing 210.2  cm (20.275 hands), held the record for tallest living horse from 2010 until his death in 2021. As of 2024, there is no living record holder. The following breeds of horse are considered draft breeds: Vehicle handling Automobile handling and vehicle handling are descriptions of

6972-562: Was America's most numerous draft breed at the turn of the 20th century. A breed developed exclusively in the U.S. was the American Cream Draft , which had a stud book established by the 1930s. Beginning in the late 19th century, and with increasing mechanization in the 20th century, especially following World War I in the US and after World War II in Europe, the popularity of the internal combustion engine, and particularly

7056-708: Was in August 1888, when Bertha Benz , wife of Benz Patent-Motorwagen inventor Karl Benz , drove 66 mi (106 km) from Mannheim to Pforzheim , Germany , and returned, in the third experimental Benz motor car, which had a maximum speed of 10 mph (16 km/h), with her two teenage sons Richard and Eugen but without the consent and knowledge of her husband. She had said she wanted to visit her mother, but also intended to generate publicity for her husband's invention, which had only been taken on short test drives before. In 1899, F. O. Stanley and his wife Flora drove their Stanley Steamer automobile, sometimes called

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