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OpenBSD s implementation of the malloc function makes use of mmap For requests greater in size than one page the entire allocation is retrieved using mmap smaller sizes are assigned from memory pools maintained by malloc within a number of bucket pages also allocated with mmap On a call to free memory is released and unmapped from the process address space using munmap This system is designed to improve security by taking advantage of the address space layout randomization and gap page features implemented as part of OpenBSD s mmap system call and to detect use after free bugs as a large memory allocation is completely unmapped after it is freed further use causes a segmentation fault and termination of the program |
Hoard is an allocator whose goal is scalable memory allocation performance Like OpenBSD s allocator Hoard uses mmap exclusively but manages memory in chunks of 64 kilobytes called superblocks Hoard s heap is logically divided into a single global heap and a number of per processor heaps In addition there is a thread local cache that can hold a limited number of superblocks By allocating only from superblocks on the local per thread or per processor heap and moving mostly empty superblocks to the global heap so they can be reused by other processors Hoard keeps fragmentation low while achieving near linear scalability with the number of threads |
Every thread has local storage for small allocations For large allocations mmap or sbrk can be used TCMalloc a malloc developed by Google has garbage collection for local storage of dead threads The TCMalloc is considered to be more than twice as fast as glibc s ptmalloc for multithreaded programs |
Operating system kernels need to allocate memory just as application programs do The implementation of malloc within a kernel often differs significantly from the implementations used by C libraries however For example memory buffers might need to conform to special restrictions imposed by DMA or the memory allocation function might be called from interrupt context This necessitates a malloc implementation tightly integrated with the virtual memory subsystem of the operating system kernel |
Because malloc and its relatives can have a strong impact on the performance of a program it is not uncommon to override the functions for a specific application by custom implementations that are optimized for application s allocation patterns The C standard provides no way of doing this but operating systems have found various ways to do this by exploiting dynamic linking One way is to simply link in a different library to override the symbols Another employed by Unix System V 3 is to make malloc and free function pointers that an application can reset to custom functions |
The largest possible memory block malloc can allocate depends on the host system particularly the size of physical memory and the operating system implementation Theoretically the largest number should be the maximum value that can be held in a sizet type which is an implementation dependent unsigned integer representing the size of an area of memory In the C99 standard and later it is available as the SIZEMAX constant from stdint h Although not guaranteed by ISO C it is usually 2 1 |
The C library implementations shipping with various operating systems and compilers may come with alternatives and extensions to the standard malloc package Notable among these is |
A seat belt also known as a seatbelt or safety belt is a vehicle safety device designed to secure the occupant of a vehicle against harmful movement that may result during a collision or a sudden stop A seat belt functions to reduce the likelihood of death or serious injury in a traffic collision by reducing the force of secondary impacts with interior strike hazards by keeping occupants positioned correctly for maximum effectiveness of the airbag if equipped and by preventing occupants being ejected from the vehicle in a crash or if the vehicle rolls over |
When in motion the driver and passengers are travelling at the same speed as the car If the car suddenly stops or crashes the driver and passengers continue at the same speed the car was going before it stopped A seatbelt applies an opposing force to the driver and passengers to prevent them from falling out or making contact with the interior of the car Seatbelts are considered Primary Restraint Systems PRS because of their vital role in occupant safety |
An analysis conducted in the United States in 1984 compared a variety of seat belt types alone and in combination with air bags The range of fatality reduction for front seat passengers was broad from 20 to 55 as was the range of major injury from 25 to 60 More recently the CDC has summarized this data by stating seat belts reduce serious crash related injuries and deaths by about half Most seatbelt malfunctions are as a result of there being too much slack in the seatbelt at the time of the accident |
Seat belts were invented by English engineer George Cayley in the mid19th century though Edward J Claghorn of New York was granted the first patent US Patent 312085 on February 10 1885 for a safety belt Claghorn was granted United States Patent 312085 for a Safety Belt for tourists painters firemen etc who are being raised or lowered described in the patent as designed to be applied to the person and provided with hooks and other attachments for securing the person to a fixed object |
In 1946 Dr C Hunter Shelden had opened a neurological practice at Huntington Memorial Hospital in Pasadena California In the early 1950s Dr Shelden had made a major contribution to the automotive industry with his idea of retractable seat belts This came about greatly in part from the high number of head injuries coming through the emergency rooms He investigated the early seat belts whose primitive designs were implicated in these injuries and deaths His findings were published in the November 5 1955 Journal of the American Medical Association JAMA in which he proposed not only the retractable seat belt but also recessed steering wheels reinforced roofs roll bars door locks and passive restraints such as the air bag Subsequently in 1959 Congress passed legislation requiring all automobiles to comply with certain safety standards |
American car manufacturers Nash in 1949 and Ford in 1955 offered seat belts as options while Swedish Saab first introduced seat belts as standard in 1958 After the Saab GT 750 was introduced at the New York Motor Show in 1958 with safety belts fitted as standard the practice became commonplace |
Glenn Sheren of Mason Michigan submitted a patent application on March 31 1955 for an automotive seat belt and was awarded US Patent 2855215 in 1958 This was a continuation of an earlier patent application that Mr Sheren had filed on September 22 1952 |
However the first modern three point seat belt the so called CIR Griswold restraint used in most consumer vehicles today was patented in 1955 US Patent 2710649 by the Americans Roger W Griswold and Hugh DeHaven Fatal car accidents were rapidly increasing in Sweden during the 1950s When a study at Vattenfall of accidents among employees revealed that the majority of casualties came from car accidents two Vattenfall engineers Bengt Odelgard and Per Olof Weman started to develop the safety belt Their work set the standard for safety belts in Swedish cars and was presented to Swedish manufacturer Volvo in the late 1950s The 3 point seatbelt was developed to its modern form by Swedish inventor Nils Bohlin for Volvo who introduced it in 1959 as standard equipment In addition to designing an effective three point belt Bohlin demonstrated its effectiveness in a study of 28000 accidents in Sweden Unbelted occupants sustained fatal injuries throughout the whole speed scale whereas none of the belted occupants were fatally injured at accident speeds below 60 mph No belted occupant was fatally injured if the passenger compartment remained intact Bohlin was granted US Patent 3043625 for the device |
The world s first seat belt law was put in place in 1970 in the state of Victoria Australia making the wearing of a seat belt compulsory for drivers and front seat passengers This legislation was enacted after trialing Hemco seatbelts designed by Desmond Hemphill 1926 2001 in the front seats of police vehicles lowering the incidence of officer injury and death |
A 2 point belt attaches at its two endpoints and was invented in the early 1900s by Jack Swearingen of Louisville Kentucky |
A lap belt is a strap that goes over the waist This was the most commonly installed type of belt prior to legislation requiring 3 point belts and is primarily found in older cars Coaches are equipped with lap belts although many newer coaches have three point belts as are passenger aircraft seats |
University of Minnesota Professor James J Crash Ryan was the inventor of and held the patent on the automatic retractable lap safety belt Ralph Nader cited Ryan s work in Unsafe at Any Speed and in 1966 President Lyndon Johnson signed two bills requiring safety belts in all passenger vehicles starting in 1968 |
Until the 1980s three point belts were commonly available only in the front outboard seats of cars the back seats were only often fitted with lap belts Evidence of the potential of lap belts to cause separation of the lumbar vertebrae and the sometimes associated paralysis or seat belt syndrome led to progressive revision of passenger safety regulations in nearly all developed countries to require 3 point belts first in all outboard seating positions and eventually in all seating positions in passenger vehicles Since September 1 2007 all new cars sold in the US require a lap and shoulder belt in the center rear seat Besides regulatory changes seat belt syndrome has led to tremendous liability for vehicle manufacturers One Los Angeles case resulted in a 45 million jury verdict against the Ford Motor Company the resulting 30 million judgment after deductions for another defendant who settled prior to trial was affirmed on appeal in 2006 |
A sash or shoulder harness is a strap that goes diagonally over the vehicle occupant s outboard shoulder and is buckled inboard of his or her lap The shoulder harness may attach to the lap belt tongue or it may have a tongue and buckle completely separate from those of the lap belt Shoulder harnesses of this separate or semiseparate type were installed in conjunction with lap belts in the outboard front seating positions of many vehicles in the North American market starting at the inception of the shoulder belt requirement of the US National Highway Traffic Safety Administration s Federal Motor Vehicle Safety Standard 208 on 1 January 1968 However if the shoulder strap is used without the lap belt the vehicle occupant is likely to submarine or slide forward in the seat and out from under the belt in a frontal collision In the mid1970s 3 point belt systems such as Chrysler s UniBelt began to supplant the separate lap and shoulder belts in American made cars though such 3 point belts had already been supplied in European vehicles such as Volvos Mercedes and Saabs for some years |
A 3 point belt is a Y shaped arrangement similar to the separate lap and sash belts but unitized Like the separate lap and sash belt in a collision the 3 point belt spreads out the energy of the moving body over the chest pelvis and shoulders Volvo introduced the first production three point belt in 1959 The first car with a three point belt was a Volvo PV 544 that was delivered to a dealer in Kristianstad on August 13 1959 However the first car model to feature the three point seat belt as a standard item was the 1959 Volvo 122 first outfitted with a two point belt at initial delivery in 1958 replaced with the three point seat belt the following year The three point belt was developed by Nils Bohlin who had earlier also worked on ejection seats at Saab Volvo then made the new seat belt design patent open in the interest of safety and made it available to other car manufacturers for free |
The BIS is a three point harness with the shoulder belt attached to the seat itself rather than to the vehicle structure The first car using this system was the Range Rover Classic Fitment was standard on the front seats from 1970 Some cars like the Renault Vel Satis use this system for the front seats A General Motors assessment concluded seat mounted 3 point belts offer better protection especially to smaller vehicle occupants though GM did not find a safety performance improvement in vehicles with seat mounted belts versus body mounted belts |
BIS type belts have been used by automakers in convertibles and pillarless hardtops where there is no B pillar to affix the upper mount of the belt Chrysler and Cadillac are well known for using this design Antique auto enthusiasts sometimes replace original seats in their cars with BIS equipped front seats providing a measure of safety not available when these cars were new However modern BIS systems typically use electronics that must be installed and connected with the seats and the vehicle s electrical system in order to function properly |
Five point harnesses are typically found in child safety seats and in racing cars The lap portion is connected to a belt between the legs and there are two shoulder belts making a total of five points of attachment to the seat A 4 point harness is similar but without the strap between the legs while a 6 point harness has two belts between the legs In NASCAR the 6 point harness became popular after the death of Dale Earnhardt who was wearing a five point harness when he suffered his fatal crash as it was first thought that his belt had broken and broke his neck at impact some teams ordered a six point harness in response |
Aerobatic aircraft frequently use a combination harness consisting of a five point harness with a redundant lap belt attached to a different part of the aircraft While providing redundancy for negative g manoeuvres which lift the pilot out of the seat they also require the pilot to unlatch two harnesses if it is necessary to parachute from a failed aircraft |
The purpose of locking retractors is to provide the seated occupant the convenience of some free movement of the upper torso within the compartment while providing a method of limiting this movement in the event of a crash Most modern seat belts are stowed on spring loaded reels called retractors equipped with inertial locking mechanisms that stop the belt from extending off the reel during severe deceleration There are two main types of inertial seat belt lock A webbing sensitive lock is based on a centrifugal clutch activated by rapid acceleration of the strap webbing from the reel The belt can be pulled from the reel only slowly and gradually as when the occupant extends the belt to fasten it A sudden rapid pull of the belt as in a sudden braking or collision event causes the reel to lock restraining the occupant in position |
A vehicle sensitive lock is based on a pendulum swung away from its plumb position by rapid deceleration or rollover of the vehicle In the absence of rapid deceleration or rollover the reel is unlocked and the belt strap may be pulled from the reel against the spring tension of the reel The vehicle occupant can move around with relative freedom while the spring tension of the reel keeps the belt taut against the occupant When the pendulum swings away from its normal plumb position due to sudden deceleration or rollover a pawl is engaged the reel locks and the strap restrains the belted occupant in position Dual sensing locking retractors use both vehicle G loading and webbing payout rate to initiate the locking mechanism |
Seatbelts in many newer vehicles are also equipped with pretensioners or web clamps or both |
Pretensioners preemptively tighten the belt to prevent the occupant from jerking forward in a crash Mercedes Benz first introduced pretensioners on the 1981 S Class In the event of a crash a pretensioner will tighten the belt almost instantaneously This reduces the motion of the occupant in a violent crash Like airbags pretensioners are triggered by sensors in the car s body and many pretensioners have used explosively expanding gas to drive a piston that retracts the belt Pretensioners also lower the risk of submarining which occurs when a passenger slides forward under a loosely fitted seat belt |
Some systems also preemptively tighten the belt during fast accelerations and strong decelerations even if no crash has happened This has the advantage that it may help prevent the driver from sliding out of position during violent evasive maneuvers which could cause loss of control of the vehicle These preemptive safety systems may prevent some collisions from happening as well as reducing injury in the event an actual collision occurs Preemptive systems generally use electric pretensioners which can operate repeatedly and for a sustained period rather than pyrotechnic pretensioners which can only operate a single time |
Webclamps clamp the webbing in the event of an accident and limit the distance the webbing can spool out caused by the unused webbing tightening on the central drum of the mechanism These belts also often incorporate an energy management loop rip stitching in which a section of the webbing is looped and stitched with a special stitching The function of this is to rip at a predetermined load which reduces the maximum force transmitted through the belt to the occupant during a violent collision reducing injuries to the occupant |
A study demonstrated that standard automotive 3 point restraints fitted with pyrotechnic or electric pretensioners were not able to eliminate all interior passenger compartment head strikes in rollover test conditions Electric pretensioners are often incorporated on vehicles equipped with precrash systems they are designed to reduce seat belt slack in a potential collision and assist in placing the occupants in a more optimal seating position The electric pretensioners also can operate on a repeated or sustained basis providing better protection in the event of an extended rollover or a multiple collision accident |
The inflatable seatbelt was invented by Donald Lewis and tested at the Automotive Products Division of Allied Chemical Corporation Inflatable seatbelts have tubular inflatable bladders contained within an outer cover When a crash occurs the bladder inflates with a gas to increase the area of the restraint contacting the occupant and also shortening the length of the restraint to tighten the belt around the occupant improving the protection The inflatable sections may be shoulder only or lap and shoulder The system supports the head during the crash better than a web only belt It also provides side impact protection In 2013 Ford began offering rear seat inflatable seat belts on a limited set of models such as the Explorer and Flex |
Seatbelts that automatically move into position around a vehicle occupant once the adjacent door is closed and or the engine is started were developed as a countermeasure against low usage rates of manual seat belts particularly in the United States The first car to feature automatic shoulder belts as standard equipment was the 1981 Toyota Cressida but the history of such belts goes back further |
The 1972 Volkswagen ESVW1 Experimental Safety Vehicle presented passive seat belts Volvo tried to develop a passive three point seatbelt In 1973 Volkswagen announced they had a functional passive seat belt The first commercial car to use automatic seat belts was the 1975 Volkswagen Golf |
Automatic seat belts received a boost in the United States in 1977 when Brock Adams United States Secretary of Transportation in the Carter Administration mandated that by 1983 every new car should have either airbags or automatic seat belts despite strong lobbying from the auto industry Adams was attacked by Ralph Nader who said that the 1983 deadline was too late Soon after General Motors began offering automatic seat belts first on the Chevrolet Chevette but by early 1979 the VW Rabbit and the Chevette were the only cars to offer the safety feature and GM was reporting disappointing sales By early 1978 Volkswagen had reported 90000 Rabbits sold with automatic seat belts A study released in 1978 by the United States Department of Transportation claimed that cars with automatic seat belts had a fatality rate of 78 per 100 million miles compared with 234 for cars with regular manual belts |
In 1981 Drew Lewis the first Transportation Secretary of the Reagan Administration influenced by studies done by the auto industry killed the previous administration s mandate the decision was overruled in a federal appeals court the following year and then by the Supreme Court In 1984 the Reagan Administration reversed its course though in the meantime the original deadline had been extended Elizabeth Dole then Transportation Secretary proposed that the two passive safety restraints be phased into vehicles gradually from vehicle model year 1987 to vehicle model year 1990 when all vehicles would be required to have either automatic seat belts or driver side air bags Though more awkward for vehicle occupants most manufacturers opted to use less expensive automatic belts rather than airbags during this time period |
When driver side airbags became mandatory on all passenger vehicles in model year 1995 most manufacturers stopped equipping cars with automatic seat belts Exceptions include the 1995 1996 Ford Escort Mercury Tracer and the Eagle Summit Wagon which had automatic safety belts along with dual airbags |
Automatic belt systems generally offer inferior occupant crash protection In systems with belts attached to the door rather than a sturdier fixed portion of the vehicle body a crash that causes the vehicle door to open leaves the occupant without belt protection In such a scenario the occupant may be thrown from the vehicle and suffer greater injury or death |
Because many automatic belt system designs compliant with the US passive restraint mandate did not meet the safety performance requirements of Canada which were not weakened to accommodate automatic belts vehicle models which had been eligible for easy importation in either direction across the US Canada border when equipped with manual belts became ineligible for importation in either direction once the US variants obtained automatic belts and the Canadian versions retained manual belts Two particular models included the Dodge Spirit and Plymouth Acclaim |
Automatic belt systems also present several operational disadvantages Motorists who would normally wear seat belts must still fasten the manual lap belt thus rendering redundant the automation of the shoulder belt Those who do not fasten the lap belt wind up inadequately protected only by the shoulder belt in a crash without a lap belt such a vehicle occupant is likely to submarine be thrown forward under the shoulder belt and be seriously injured Motorized or door affixed shoulder belts hinder access to the vehicle making it difficult to enter and exit particularly if the occupant is carrying items such as a box or a purse Vehicle owners tend to disconnect the motorized or door affixed shoulder belt to relieve the nuisance of entering and exiting the vehicle leaving only a lap belt for crash protection Also many automatic seat belt systems are incompatible with child safety seats or only compatible with special modifications |
Starting in 1971 and ending in 1972 the United States conducted a research project on seat belt effectiveness on a total of 40000 vehicle occupants using car accident reports collected during that time Of these 40000 occupants 18 were reported wearing lap belts or two point safety belts 2 were reported wearing a three point safety belt and the remaining 80 was reported as wearing no safety belt The results concluded that users of the two point lap belt had a 73 lower fatality rate a 53 lower serious injury rate and a 38 lower injury rate when compared with the occupants that were reported unrestrained Similarly users of the three point safety belt had a 60 lower serious injury rate and a 41 lower rate of all other injuries Out of the 2 described as wearing a three point safety belt no fatalities were reported |
This study and others led to the Restraint Systems Evaluation Program RSEP started by the National Highway Traffic Safety Administration in 1975 to increase the reliability and authenticity of past studies A study as part of this program used data taken from 15000 tow away accidents that involved only car models made between 1973 and 1975 The study found that for injuries considered moderate or worse individuals wearing a three point safety belt had a 565 lower injury rate than those wearing no safety belt The study also concluded that the effectiveness of the safety belt did not differ with size of car It was determined that the variation among results of the many studies conducted in the 1960s and 70s was due to the use of different methodologies and could not be attributed to any significant variation in the effectiveness of safety belts |
Helping to improve safety apparatuses in vehicles injury testing and seat belt effectiveness are being tested today by Wayne State University s Automotive Safety Research Group as well as other researchers Wayne State s Bioengineering Center uses human cadavers in their crash test research Albert King the Center s director wrote in his 1995 article titled Humanitarian Benefits of Cadaver Research on Injury Prevention that that use of cadavers in this type of research since 1987 has saved and will continue to save nearly 8500 lives each year due to the vehicle safety improvements made possible by human cadaver testing He also indicates that due to the improvements made to three point safety belts an average of 61 lives are saved per year |
The New Car Assessment Program NCAP was put in place by the United States National Highway Traffic Safety Administration in 1979 The NCAP is a government program that evaluates vehicle safety designs and sets standards for foreign and domestic automobile companies The agency has put in place a rating system and requires access to safety test results As of September 2007 manufacturers are required to place a NCAP star rating on the automobile price sticker |
Research and development efforts are ongoing to improve the safety performance of vehicle seatbelts Some experimental designs have included |
In 1955 as a 1956 package Ford offered lap only seat belts in the rear seats as an option within the Lifeguard safety package In 1967 Volvo started to install lap belts in the rear seats In 1972 Volvo upgraded the rear seat belts to a three point belt |
In crashes unbelted rear passengers increase the risk of belted front seat occupants death by nearly five times |
As with adult drivers and passengers the advent of seat belts was accompanied by calls for their use by child occupants including legislation requiring such use Generally children using adult seat belts suffer significantly lower injury risk when compared to nonbuckled children |
The UK extended compulsory seatbelt wearing to child passengers under the age of 14 in 1989 It was observed that this measure was accompanied by a 10 increase in fatalities and a 12 increase in injuries among the target population In crashes small children who wear adult seatbelts can suffer seat belt syndrome injuries including severed intestines ruptured diaphragms and spinal damage There is also research suggesting that children in inappropriate restraints are at significantly increased risk of head injury one of the authors of this research has been quoted as claiming that The early graduation of kids into adult lap and shoulder belts is a leading cause of child occupant injuries and deaths |
As a result of such findings many jurisdictions now advocate or require child passengers to use specially designed child restraints Such systems include separate child sized seats with their own restraints and booster cushions for children using adult restraints In some jurisdictions children below a certain size are forbidden to travel in front car seats |
In Europe and some other parts of the world most modern cars include a seat belt reminder light for the driver and some also include a reminder for the passenger when present activated by a pressure sensor under the passenger seat Some cars will intermittently flash the reminder light and sound the chime until the driver and sometimes the front passenger if present fasten their seatbelts |
In North America cars sold since the early 1970s have included an audiovisual reminder system consisting of a tell tale light on the dashboard and a buzzer or chime reminding the driver and passengers to fasten their belts Originally these lights were accompanied by a warning buzzer whenever the transmission was in any position except park if either the driver was not buckled up or as determined by a pressure sensor in the passenger s seat if there was a passenger there not buckled up However this was considered by many to be a major annoyance as the light would be on and the buzzer would sound continuously if front seat passengers were not buckled up Therefore people who did not wish to buckle up would defeat this system by fastening the seat belts with the seat empty and leaving them that way |
To combat this dangerous habit in 1971 NHTSA amended Federal Motor Vehicle Safety Standard No 208 FMVSS 208 to require a seat belt starter interlock system to prevent passenger cars from being started with an unbelted front seat occupant This mandate applied to passenger cars built after August 1973 ie starting with the 1974 model year The specifications required the system to permit the car to be started only if the belt of an occupied seat were fastened after the occupant sat down so prebuckling the belts would not defeat the system The interlock systems used logic modules complex enough to require special diagnostic computers and were not entirely dependable an override button was provided under the hood of equipped cars permitting one but only one free starting attempt each time it was pressed However the interlock system spurred severe backlash from an American public who largely rejected seat belts In 1974 Congress acted to prohibit NHTSA from requiring or permitting a system that prevents a vehicle from starting or operating with an unbelted occupant or that gives an audible warning of an unfastened belt for more than 8 seconds after the ignition is turned on This prohibition took effect on 27 October 1974 shortly after the 1975 model year began |
In response to the Congressional action NHTSA once again amended FMVSS 208 requiring vehicles to come with a seat belt reminder system that gives an audible signal for 4 to 8 seconds and a warning light for at least 60 seconds after the ignition is turned on if the driver s seat belt is not fastened This is called a seat belt reminder SBR system In the mid1990s an insurance company from Sweden called Folksam worked with Saab and Ford to determine the requirements for the most efficient seat belt reminder One characteristic of the optimal SBR according to the research is that the audible warning becomes increasingly penetrating the longer the seat belt remains unfastened |
In 2003 the Transportation Research Board Committee chaired by two psychologists reported that ESBRs could save an additional 1000 lives a year Research by the Insurance Institute for Highway Safety found that Ford s ESBR which provides an intermittent chime for up to five minutes if the driver is unbelted sounding for 6 seconds then pausing for 30 increased seat belt use by 5 percent Farmer and Wells found that driver fatality rates were 6 lower for vehicles with ESBR compared with otherwise identical vehicles without |
In 2001 Congress directed NHSTA to study the benefits of technology meant to increase the use of seat belts NHSTA found that seat belt usage had increased to 73 since the initial introduction of the SBR system In 2002 Ford demonstrated that seat belts were used more in Fords with seat belt reminders than in those without 76 and 71 respectively In 2007 Honda conducted a similar study and found that 90 of people who drove Hondas with seat belt reminders used a seat belt while 84 of people who drove Hondas without seat belt reminders used a seat belt |
Observational studies of car crash morbidity and mortality experiments using both crash test dummies and human cadavers indicate that wearing seat belts greatly reduces the risk of death and injury in the majority of car crashes |
This has led many countries to adopt mandatory seat belt wearing laws It is generally accepted that in comparing like for like accidents a vehicle occupant not wearing a properly fitted seat belt has a significantly and substantially higher chance of death and serious injury One large observation studying using US data showed that the odds ratio of crash death is 046 with a three point belt when compared with no belt In another study that examined injuries presenting to the ER pre and postseat belt law introduction it was found that 40 more escaped injury and 35 more escaped mild and moderate injuries |
The effects of seat belt laws are disputed by those who observe that their passage did not reduce road fatalities There was also concern that instead of legislating for a general protection standard for vehicle occupants laws that required a particular technical approach would rapidly become dated as motor manufacturers would tool up for a particular standard which could not easily be changed For example in 1969 there were competing designs for lap and 3 point seat belts rapidly tilting seats and air bags being developed But as countries started to mandate seat belt restraints the global auto industry invested in the tooling and standardized exclusively on seat belts and ignored other restraint designs such as air bags for several decades |
As of 2016 seat belt laws can be divided into two categories primary and secondary A primary seat belt law allows an officer to issue a citation for lack of seatbelt use without any other citation whereas a secondary seat belt law allows an officer to issue a seat belt citation only in the presence of a different violation In the United States fifteen states enforce secondary laws while 34 states as well as the District of Columbia American Samoa Guam the Northern Mariana Islands Puerto Rico and the Virgin Islands enforce primary seat belt laws New Hampshire lacks both a primary and secondary seat belt law |
Some have proposed that the number of deaths was influenced by the development of risk compensation which says that drivers adjust their behavior in response to the increased sense of personal safety wearing a seat belt provides |
In one trial subjects were asked to drive go karts around a track under various conditions It was found that subjects who started driving unbelted drove consistently faster when subsequently belted Similarly a study of habitual nonseatbelt wearers driving in freeway conditions found evidence that they had adapted to seatbelt use by adopting higher driving speeds and closer following distances A 2001 analysis of US crash data aimed to establish the effects of seatbelt legislation on driving fatalities and found that previous estimates of seatbelts effectiveness had been significantly overstated According to the analysis used seatbelts were claimed to have decreased fatalities by 135 for each 10 increase in seatbelt use The study controlled for endogenous motivations of seat belt use which it is claimed creates an artificial correlation between seat belt use and fatalities leading to the conclusion that seatbelts cause fatalities For example drivers in high risk areas are more likely to use seat belts and are more likely to be in accidents creating a noncausal correlation between seatbelt use and mortality After accounting for the endogeneity of seatbelt usage Cohen and Einav found no evidence that the risk compensation effect makes seatbelt wearing drivers more dangerous a finding at variance with other research |
Other statistical analyses have included adjustments for factors such as increased traffic and other factors such as age and based on these adjustments a reduction of morbidity and mortality due to seat belt use has been claimed However Smeed s law predicts a fall in accident rate with increasing car ownership and has been demonstrated independently of seat belt legislation |
In the US six states California Florida Louisiana New Jersey New York and Texas require seat belts on school buses |
Pros and cons had been alleged about the use of seatbelts in school buses School buses which are much bigger in size than the average vehicle allow for the mass transportation of students from place to place The American School Bus Council states in a brief article saying that The children are protected like eggs in an egg carton compartmentalized and surrounded with padding and structural integrity to secure the entire container ASBC Although school buses are considered safe for mass transit of students this will not guarantee that the students will be injury free if an impact were to occur Seatbelts in buses are sometimes believed to make recovering from a roll or tip harder for students and staff as they could be easily trapped in their own safety belt |
In 2015 for the first time NHTSA endorsed seat belts on school buses |
In the European Union all new long distance buses and coaches must be fitted with seat belts |
Australia has required lap sash seat belts in new coaches since 1994 These must comply with Australian Design Rule 68 which requires the seat belt seat and seat anchorage to withstand 20g deceleration and an impact by an unrestrained occupant to the rear |
In the United States NHTSA has now required lap shoulder seat belts in new overthe road buses includes most coaches starting in 2016 |
The use of seatbelts in trains has been investigated Concerns about survival space intrusion in train crashes and increased injuries to unrestrained or incorrectly restrained passengers led the researchers to discourage the use of seat belts in trains |
Lap belts are found on all passenger aircraft Many civil aviation authorities require a fasten seat belt sign in passenger aircraft that can be activated by a pilot during takeoff turbulence and landing The International Civil Aviation Organization recommends the use of child restraints |
The Maryland Toleration Act also known as the Act Concerning Religion was a law mandating religious tolerance for Trinitarian Christians It was passed on April 21 1649 by the assembly of the Maryland colony in St Mary s City It was the second law requiring religious tolerance in the British North American colonies and created one of the pioneer statutes passed by the legislative body of an organized colonial government to guarantee any degree of religious liberty Specifically the bill now usually referred to as the Toleration Act granted freedom of conscience to all Christians The colony which became Rhode Island passed a series of laws the first in 1636 which prohibited religious persecution including against nonTrinitarians Rhode Island was also the first government to separate church and state Historians argue that it helped inspire later legal protections for freedom of religion in the United States The Calvert family who founded Maryland partly as a refuge for English Catholics sought enactment of the law to protect Catholic settlers and those of other religions that did not conform to the dominant Anglicanism of Britain and her colonies |
The Act allowed freedom of worship for all Trinitarian Christians in Maryland but sentenced to death anyone who denied the divinity of Jesus It was revoked in 1654 by William Claiborne a Virginian who had been appointed as a commissioner by Oliver Cromwell he was an Anglican a Puritan sympathizer and strongly hostile to the Catholic Religion When the Calverts regained control of Maryland the Act was reinstated before being repealed permanently in 1692 following the events of the Glorious Revolution and the Protestant Revolution in Maryland As the first law on religious tolerance in the British North America it influenced related laws in other colonies and portions of it were echoed in the writing of the First Amendment to the United States Constitution which enshrined religious freedom in American law |
The Maryland colony was founded by Cecil Calvert in 1634 Like his father George Calvert who had originated the efforts that led to the colony s charter Cecil Calvert was Catholic at a time when England was dominated by the Anglican Church The Calverts intended the colony as a haven for Catholics fleeing England and as a source of income for themselves and their descendants Many of Maryland s first settlers were Catholic including at least two Catholic priests one of whom became the earliest chronicler of the colony s history But whatever Calvert s intentions Maryland was a colony of an Anglican nation Its charter had been granted by an Anglican king and seems to have assumed that the Church of England would be its official church Anglican and later Puritan newcomers quickly came to outnumber the early Catholic settlers Thus by 1649 when the law was passed the colonial assembly was dominated by Protestants and the law was in effect an act of Protestant tolerance for Catholics rather than the reverse |
From Maryland s earliest days Cecil Calvert had enjoined its colonists to leave religious rivalries behind Along with giving instructions on the establishment and defense of the colony he asked the men he appointed to lead it to ensure peace between Protestants and Catholics He also asked the Catholics to practice their faith as privately as possible so as not to disturb that peace The Ordinance of 1639 Maryland s earliest comprehensive law expressed a general commitment to the rights of man but did not specifically detail protections for religious minorities of any kind Peace prevailed until the English Civil War which opened religious rifts and threatened Calvert s control of Maryland In 1647 after the death of Governor Leonard Calvert Protestants seized control of the colony Cecil Calvert 2nd Baron Baltimore quickly regained power but recognized that religious tolerance not specifically enshrined in law was vulnerable This recognition was combined with the arrival of a group of Puritans whom Calvert had induced to establish Providence now Annapolis by guaranteeing their freedom of worship Partially to confirm the promises he made to them Calvert wrote the Maryland Toleration Act and encouraged the colonial assembly to pass it They did so on April 21 1649 |
The Maryland Toleration Act was an act of tolerance allowing specific religious groups to practice their religion without being punished but retaining the ability to revoke that right at any time It also only granted tolerance to Christians who believed in the Trinity The law was very explicit in limiting its effects to Christians |
no person or persons professing to believe in Jesus Christ shall from henceforth be anyways troubled Molested or discountenanced for or in respect of his or her religion nor in the free exercise thereof within this Province |
Settlers who blasphemed by denying either the Trinity or the divinity of Jesus Christ could be punished by execution or the seizure of their lands That meant that Jews Unitarians and other dissenters from Trinitarian Christianity were practicing their religions at risk to their lives Any person who insulted the Virgin Mary the apostles or the evangelists could be whipped jailed or fined Otherwise Trinitarian Christians right to worship was protected The law outlawed the use of heretic and other religious insults against them This attempt to limit the use of religious slurs and insults has been described as the first attempt in the world to limit the use of hate speech |
The law was used in at least one attempt to prosecute a nonChristian In 1658 a Jew named Jacob Lumbrozo was accused of blasphemy after saying that Jesus was not the son of God and that the miracles described in the New Testament were conjuring tricks Lumbrozo did not deny having said such things but argued that he had only been responding to questions asked of him He was held for trial but the case was later dismissed and he was given full citizenship as a condition of the restoration of Calvert s rule following the English Civil War |
The law had its detractors even among those groups protected by it Puritans were concerned that the act and the proprietary government in general were royalist They were also concerned that by swearing allegiance to Calvert who was Catholic they were being required to submit to the Pope whom they considered to be the antichrist Some Anglicans also opposed the law believing that the Church of England should be the colony s sole established church |
In 1654 only five years after its passage the Act was repealed Two years earlier the colony had been seized by Protestants following the execution of King Charles I of England and the outbreak of the English Civil War In the early stages of that conflict the colonial assembly of Maryland and its neighbors in Virginia had publicly declared their support for the King Parliament appointed Protestant commissioners loyal to their cause to subdue the colonies and two of them the Virginian William Claiborne and Puritan leader Richard Bennett took control of the colonial government in St Mary s City in 1652 In addition to repealing the Maryland Toleration Act with the assistance of Protestant assemblymen Claiborne and Bennett passed a new law barring Catholics from openly practicing their religion Calvert regained control after making a deal with the colony s Protestants and in 1657 the Act was again passed by the colonial assembly This time it would last more than thirty years until 1692 |
Following the Glorious Revolution of 1688 in England when the Catholic King James II of England was deposed and the Protestant William III ascended the throne a rebellion of Maryland Puritan Protestants overthrew Calvert s rule They quickly rescinded the Toleration Act and banned public practice of Catholicism and it would never be reinstated under colonial rule In fact the colony established the Church of England as its official church in 1702 and explicitly barred Catholics from voting in 1718 The Calvert family regained control over the colony in 1715 but only after Benedict Calvert converted to Protestantism His political control remained tense enough that he did not risk an attempt to reinstate protections for Catholics It took until the era of the American Revolution for religious tolerance or freedom to again become the practice in Maryland |
While the law did not secure religious freedom and while it included severe limitations it was nonetheless a significant milestone It predates the Enlightenment which is generally considered to be when the idea of religious freedom took root and stands as the first legal guarantee of religious tolerance in American and British history Later laws ensuring religious tolerance and freedom including the British Act of Toleration of 1689 the Holy Experiment in Pennsylvania and laws concerning religion in other colonies such as South Carolina may have been influenced by its example According to historian Robert Brugger the measure marked a notable departure from Old World oppression It was not until the passage of the signed First Amendment to the Constitution over a century later that religious freedom was enshrined as a fundamental guarantee but even that document echoes the Toleration Act in its use of the phrase free exercise thereof Thus despite its lack of a full guarantee of religious freedom or broad based tolerance the law is a significant step forward in the struggle for religious liberty |
Avengers Age of Ultron is a 2015 American superhero film based on the Marvel Comics superhero team the Avengers produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures It is the sequel to 2012 s The Avengers and the eleventh film in the Marvel Cinematic Universe MCU The film was written and directed by Joss Whedon and features an ensemble cast that includes Robert Downey Jr Chris Hemsworth Mark Ruffalo Chris Evans Scarlett Johansson Jeremy Renner Don Cheadle Aaron Taylor Johnson Elizabeth Olsen Paul Bettany Cobie Smulders Anthony Mackie Hayley Atwell Idris Elba Stellan Skarsgrd James Spader and Samuel L Jackson In Avengers Age of Ultron the Avengers fight Ultron an artificial intelligence obsessed with causing human extinction |
The sequel was announced in May 2012 after the successful release of The Avengers Whedon the director of the first film was brought back on board in August and a release date was set By April 2013 Whedon had completed a draft of the script and casting began in June with the resigning of Downey Second unit filming began in February 2014 in South Africa with principal photography taking place between March and August 2014 The film was primarily shot at Shepperton Studios in Surrey England with additional footage filmed in Italy South Korea Bangladesh New York City and various locations around England While in post production the film was converted to 3D and over 3000 visual effects shots were added |
Avengers Age of Ultron premiered in Los Angeles on April 13 2015 and was released on May 1 2015 in North America in 3D and IMAX 3D The film received generally positive reviews from critics and grossed over 14 billion worldwide making it the seventh highest grossing film in history and the fourth highest grossing film of 2015 A sequel Avengers Infinity War is scheduled to be released on May 4 2018 and another untitled sequel is scheduled for May 3 2019 |
In the Eastern European country of Sokovia the Avengers Tony Stark Steve Rogers Thor Bruce Banner Natasha Romanoff and Clint Barton raid a Hydra facility commanded by Baron Wolfgang von Strucker who has been experimenting on humans using the scepter previously wielded by Loki They encounter two of Strucker s test subjects twins Pietro Maximoff who has superhuman speed and Wanda Maximoff who can manipulate minds and project energy and apprehend Strucker while Stark retrieves Loki s scepter |
Stark and Banner discover an artificial intelligence within the scepter s gem and secretly decide to use it to complete Stark s Ultron global defense program The unexpectedly sentient Ultron believing he must eradicate humanity to save Earth eliminates Stark s AI JARVIS and attacks the Avengers at their headquarters Escaping with the scepter Ultron uses the resources in Strucker s Sokovia base to upgrade his rudimentary body and build an army of robot drones Having killed Strucker he recruits the Maximoffs who hold Stark responsible for their parents deaths by his company s weapons and goes to the base of arms dealer Ulysses Klaue to obtain Wakandan vibranium The Avengers attack Ultron and the Maximoffs but Wanda subdues them with haunting visions causing the Hulk Banner to rampage until Stark stops him with his antiHulk armor |
A worldwide backlash over the resulting destruction and the fears Wanda s hallucinations incited send the team into hiding at a safe house Thor departs to consult with Dr Erik Selvig on the meaning of the apocalyptic future he saw in his hallucination while Romanoff and Banner plan to flee together after realizing a mutual attraction However Nick Fury arrives and encourages the team to form a plan to stop Ultron In Seoul Ultron forces the team s friend Dr Helen Cho to use her synthetic tissue technology together with vibranium and the scepter s gem to perfect a new body for him As Ultron uploads himself into the body Wanda is able to read his mind discovering his plan for human extinction the Maximoffs turn against Ultron Rogers Romanoff and Barton find Ultron and retrieve the synthetic body but Ultron captures Romanoff |
The Avengers fight amongst themselves when Stark secretly uploads JARVIS who is still operational after hiding from Ultron inside the Internet into the synthetic body Thor returns to help activate the body explaining that the gem on its brow one of the six Infinity Stones the most powerful objects in existence was part of his vision This Vision and the Maximoffs accompany the Avengers to Sokovia where Ultron has used the remaining vibranium to build a machine to lift a large part of the capital city skyward intending to crash it into the ground to cause global extinction Banner rescues Romanoff who awakens the Hulk for the battle The Avengers fight Ultron s army while Fury arrives in a Helicarrier with Maria Hill James Rhodes and SHIELD agents to evacuate civilians Pietro dies when he shields Barton from gunfire and a vengeful Wanda abandons her post to destroy Ultron s primary body which allows one of his drones to activate the machine The city plummets but Stark and Thor overload the machine and shatter the landmass In the aftermath the Hulk unwilling to endanger Romanoff by being with her departs in a Quinjet while the Vision confronts Ultron s last remaining body |
Later with the Avengers having established a new base run by Fury Hill Cho and Selvig Thor returns to Asgard to learn more about the forces he suspects have manipulated recent events As Stark leaves and Barton retires Rogers and Romanoff prepare to train new Avengers Rhodes the Vision Sam Wilson and Wanda |
In a midcredits scene Thanos dissatisfied by the failures of his pawns dons a gauntlet and vows to retrieve the Infinity Stones himself |