Healthy and safety

Healthy and safety
Road traffic safety refers to the methods and measures used to prevent road users from being killed or seriously injured. Typical road users include pedestrians, cyclists, motorists, vehicle passengers, horse riders, and passengers of on-road public transport (mainly buses and trams).
Best practices in modern road safety strategy:
The basic strategy of a Safe System approach is to ensure that in the event of a crash, the impact energies remain below the threshold likely to produce either death or serious injury. This threshold will vary from crash scenario to crash scenario, depending upon the level of protection offered to the road users involved. For example, the chances of survival for an unprotected pedestrian hit by a vehicle diminish rapidly at speeds greater than 30 km/h, whereas for a properly restrained motor vehicle occupant the critical impact speed is 50 km/h (for side impact crashes) and 70 km/h (for head-on crashes).
— International Transport Forum, Towards Zero, Ambitious Road Safety Targets and the Safe System Approach, Executive Summary page.
As sustainable solutions for classes of road safety have not been identified, particularly low-traffic rural and remote roads, a hierarchy of control should be applied, similar to classifications used to improve occupational safety and health. At the highest level is sustainable prevention of serious injury and death crashes, with sustainable requiring all key result areas to be considered. At the second level is real-time risk reduction, which involves providing users at severe risk with a specific warning to enable them to take mitigating action. The third level is about reducing the crash risk which involves applying the road-design standards and guidelines (such as from AASHTO), improving driver behavior and enforcement.
Road traffic crashes are one of the world's largest public health and injury prevention problems. The problem is all the more acute because the victims are overwhelmingly healthy before their crashes. According to the World Health Organization (WHO), more than 1 million people are killed on the world's roads each year.[3] A report published by the WHO in 2004 estimated that some 1.2 million people were killed and 50 million injured in traffic collisions on the roads around the world each year[4] and was the leading cause of death among children 10–19 years of age. The report also noted that the problem was most severe in developing countries and that simple prevention measures could halve the number of deaths.
The standard measures used in assessing road safety interventions are fatalities and killed or seriously injured (KSI) rates, usually per billion (109) passenger kilometres. Countries caught in the old road safety paradigm, replace KSI rates with crash rates – for example, crashes per million vehicle miles.
Vehicle speed within the human tolerances for avoiding serious injury and death is a key goal of modern road design because impact speed affects the severity of injury to both occupants and pedestrians. For occupants, Joksch (1993) found the probability of death for drivers in multi-vehicle collisions increased as the fourth power of impact speed (often referred to by the mathematical term δv ("delta V"), meaning change in velocity). Injuries are caused by sudden, severe acceleration (or deceleration); this is difficult to measure. However, crash reconstruction techniques can estimate vehicle speeds before a crash. Therefore, the change in speed is used as a surrogate for acceleration. This enabled the Swedish Road Administration to identify the KSI risk curves using actual crash reconstruction data which led to the human tolerances for serious injury and death referenced above.
Interventions are generally much easier to identify in the modern road safety paradigm, whose focus is on the human tolerances for serious injury and death. For example, the elimination of head-on KSI crashes simply required the installation of an appropriate median crash barrier. Also, roundabouts, often with speed reducing approaches, encounter very few KSI crashes.
The old road safety paradigm of purely crash risk is a far more complex matter. Contributing factors to highway crashes may be related to the driver (such as driver error, illness, or fatigue), the vehicle (brake, steering, or throttle failures), or the road itself (lack of sight distance, poor roadside clear zones, etc.). Interventions may seek to reduce or compensate for these factors, or reduce the severity of crashes. A comprehensive outline of interventions areas can be seen in management systems for road safety. Study conducted in Finland revealed that the fatality risk is increased most when a collision type is either pedestrian or meeting of the vehicles.
In addition to management systems, which apply predominantly to networks in built-up areas, another class of interventions relates to the design of roadway networks for new districts. Such interventions explore the configurations of a network that will inherently reduce the probability of collisions.[8]
Interventions for the prevention of road traffic injuries are often evaluated; the Cochrane Library has published a wide variety of reviews of interventions for the prevention of road traffic injuries.
For road traffic safety purposes it can be helpful to classify roads into three usages: built-up urban streets with slower speeds, greater densities, and more diversity among road users; non built-up rural roads with higher speeds; and major highways (motorways/ Interstates/ freeways/ Autobahns, etc.) reserved for motor-vehicles, and which are often designed to minimize and attenuate crashes. Most injuries occur on urban streets but most fatalities on rural roads, while motorways are the safest in relation to distance traveled. For example, in 2013, German autobahns carried 31% of motorized road traffic (in travel-kilometres) while accounting for 13% of Germany's traffic deaths. The autobahn fatality rate of 1.9 deaths per billion-travel-kilometres compared favorably with the 4.7 rate on urban streets and 6.6 rate on rural roads.




Utrecht has specially painted bicycle-only lanes.
On neighborhood roads where many vulnerable road users, such as pedestrians and bicyclists can be found, traffic calming can be a tool for road safety. Though not strictly a traffic calming measure, mini-traffic circles implanted in normal intersections of neighbourhood streets have been shown to reduce collisions at intersections dramatically[18] (see picture). Shared space schemes, which rely on human instincts and interactions, such as eye contact, for their effectiveness, and are characterised by the removal of traditional traffic signals and signs, and even by the removal of the distinction between carriageway (roadway) and footway (sidewalk), are also becoming increasingly popular. Both approaches can be shown to be effective.[19]
For planned neighbourhoods, studies recommend new network configurations, such as the Fused Grid or 3-Way Offset. These layout models organize a neighbourhood area as a zone of no cut-through traffic by means of loops or dead-end streets. They also ensure that pedestrians and bicycles have a distinct advantage by introducing exclusive shortcuts by path connections through blocks and parks. Such a principle of organization is referred to as "Filtered Permeability" implying a preferential treatment of active modes of transport. These new patterns, which are recommended for laying out neighbourhoods, are based on analyses of collision data of large regional districts and over extended periods. They show that four-way intersections combined with cut-through traffic are the most significant contributors to increased collisions.
Modern safety barriers are designed to absorb impact energy and minimize the risk to the occupants of cars and bystanders. For example, most side rails are now anchored to the ground, so that they cannot skewer a passenger compartment. Most light poles are designed to break at the base rather than violently stop a car that hits them. Some road fixtures such as signs and fire hydrants are designed to collapse on impact. authorities have removed trees in the vicinity of roads; while the idea of "dangerous trees" has attracted a certain amount of skepticism, unforgiving objects such as trees can cause severe damage and injury to errant road users. Safety barriers can provide some combination of physical protection and visual protection depending on their environment. Physical protection is important for protecting sensitive building and pedestrian areas. Visual protection is necessary to alert drivers to changes in road patterns.
Most roads are cambered (crowned), that is, made so that they have rounded surfaces, to reduce standing water and ice, primarily to prevent frost damage but also increasing traction in poor weather. Some sections of road are now surfaced with porous bitumen to enhance drainage; this is particularly done on bends. These are just a few elements of highway engineering. As well as that, there are often grooves cut into the surface of cement highways to channel water away, and rumble strips at the edges of highways to rouse inattentive drivers with the loud noise they make when driven over. In some cases, there are raised markers between lanes to reinforce the lane boundaries; these are often reflective.
In pedestrian areas, speed bumps are often placed to slow cars, preventing them from going too fast near pedestrians.
Poor road surfaces can lead to safety problems. If too much asphalt or bituminous binder is used in asphalt concrete, the binder can 'bleed' or flush' to the surface, leaving a very smooth surface that provides little traction when wet. Certain kinds of stone aggregate become very smooth or polished under the constant wearing action of vehicle tyres, again leading to poor wet-weather traction. Either of these problems can increase wet-weather crashes by increasing braking distances or contributing to loss of control. If the pavement is insufficiently sloped or poorly drained, standing water on the surface can also lead to wet-weather crashes due to hydroplaning.
Lane markers in some countries and states are marked with cat's eyes, Botts' dots or reflective raised pavement markers that do not fade like paint. Botts dots are not used where it is icy in the winter, because frost and snowplows can break the glue that holds them to the road, although they can be embedded in short, shallow trenches carved in the roadway, as is done in the mountainous regions of California.
Road hazards and intersections in some areas are now usually marked several times, roughly five, twenty, and sixty seconds in advance so that drivers are less likely to attempt violent manoeuvres.
Most road signs and pavement marking materials are retro-reflective, incorporating small glass spheres[24] or prisms to more efficiently reflect light from vehicle headlights back to the driver's eyes.
Turning across traffic[edit]
Turning across traffic (i.e., turning left in right-hand drive countries, turning right in left-hand drive countries) poses several risks. The more serious risk is a collision with oncoming traffic. Since this is nearly a head-on collision, injuries are common. It is the most common cause of fatalities in a built-up area. Another major risk is involvement in a rear-end collision while waiting for a gap in oncoming traffic.
Countermeasures for this type of collision include:
Addition of left turn lanes[25]
Providing protected turn phasing at signalized intersections[26]
Using indirect turn treatments such as the Michigan left
Converting conventional intersections to roundabouts[25]
In the absence of these facilities as a driver about to turn:
Keep your wheels straight, so that in the event of a rear end shunt, you are not pushed into on-coming traffic.
When you think it is clear, look away, to the road that you are entering. There is an optical illusion that, after a time, presents an oncoming vehicle as further away and travelling slower. Looking away breaks this illusion.
There is no presumption of negligence which arises from the bare fact of a collision at an intersection,[27] and circumstances may dictate that a left turn is safer than to turn right. The American Association of State Highway Transportation Officials (AASHTO) recommends in their publication Geometric Design of Highways and Streets[28] that left or right turns are to be provided the same time gap.[29] Some states have recognized this in statute, and a presumption of negligence is only raised because of the turn if and only if the turn was prohibited by an erected sign.[30]
Turns across traffic have been shown to be problematic for older drivers.[31]
Designing for pedestrians and cyclists[edit]
Pedestrians and cyclists are among the most vulnerable road users[32] and in some countries constitute over half of all road deaths. Interventions aimed at improving safety of non-motorised users:
Sidewalks (or pavements in British English) of suitable width for pedestrian traffic
Pedestrian crossings close to the desire line which allow pedestrians to cross roads safely
Segregated pedestrian routes and cycle lanes away from the main highway
Overbridges (tend to be unpopular with pedestrians and cyclists due to additional distance and effort)
Underpasses (these can pose heightened risk from crime if not designed well, can work for cyclists in some cases)
Traffic calming and speed humps
Low speed limits that are rigorously enforced, possibly by speed cameras
Shared space schemes giving ownership of the road space and equal priority to all road users, regardless of mode of use
Pedestrian barriers to prevent pedestrians crossing dangerous locations
Cycling infrastructure
Protected intersection
American passive traffic safety measures which were adopted in the mid-20th century created roadways which were forgiving to motorists traveling at high speeds but which de-prioritized cycling and pedestrian facilities. Passive traffic safety policies led to excessively wide streets, clear zones adjacent to roadways, wide turn radii and a focus on protecting drivers from the consequences of high speeds. Passive traffic safety measures sought to avoid influencing the behavior of drivers while giving automobiles maximum convenience.[33] Recent complete street policies seek to create design-oriented traffic safety improvements which actively slow drivers down by narrowing roadways while better accommodating pedestrians and cyclists.
Pedestrians' advocates question the equitability of schemes if they impose extra time and effort on the pedestrian to remain safe from vehicles, for example overbridges with long slopes or steps up and down, underpasses with steps and addition possible risk of crime and at-grade crossings off the desired crossing line. Make Roads Safe was criticised in 2007 for proposing such features. Successful pedestrian schemes tend to avoid over-bridges and underpasses and instead use at-grade crossings (such as pedestrian crossings) close to the intended route. Successful cycling schemes by contrast avoid frequent stops even if some additional distance is involved, because cyclists expend more energy when starting off.
In Costa Rica 57% of road deaths are pedestrians. However, a partnership between AACR, Cosevi, MOPT and iRAP has proposed the construction of 190 km of pedestrian footpaths and 170 pedestrian crossings which could save over 9000 fatal or serious injuries over 20 years.[34] In Robert Beadles' book, He outlines why it is so important to have traffic control and why it is the most important aspect of keeping citizens safe on a motorway, "Correct traffic control and road traffic safety is vital to keeping communities safe and people in our neighborhoods safe from danger."

Safe from traffic for cycling along a fully segregated Fietspad, properly designed cycling infrastructure in Amsterdam.
Shared space[edit]
Main article: Shared space

A shared space in Brighton (UK)
By 1947 the Pedestrians' Association was suggesting that many of the safety features being introduced (speed limits, traffic calming, road signs and road markings, traffic lights, Belisha beacons, pedestrian crossings, cycle lanes, etc.) were potentially self-defeating because "every nonrestrictive safety measure, however admirable in itself, is treated by the drivers as an opportunity for more speeding, so that the net amount of danger is increased and the latter state is worse than the first."[35]
During the 1990s a new approach, known as 'shared space' was developed which removed many of these features in some places has attracted the attention of authorities around the world.[36][37] The approach was developed by Hans Monderman who believed that "if you treat drivers like idiots, they act as idiots"[38] and proposed that trusting drivers to behave was more successful than forcing them to behave.[39] Professor John Adams, an expert on risk compensation suggested that traditional traffic engineering measures assumed that motorists were "selfish, stupid, obedient automatons who had to be protected from their own stupidity" and non-motorists were treated as "vulnerable, stupid, obedient automatons who had to be protected from cars – and their own stupidity".[40]
Reported results indicate that the 'shared space' approach leads to significantly reduced traffic speeds, the virtual elimination of road casualties, and a reduction in congestion.[39] Living streets share some similarities with shared spaces. The woonerven also sought to reduce traffic speeds in community and housing zones by the use of lower speed limits enforced by the use of special signage and road markings, the introduction of traffic calming measures, and by giving pedestrians priority over motorists.
Non built-up areas[edit]
Roads outside built-up area also known as rural roads not including motorways are roads which are not classified as urban road and which are not classified as motorway. In the European Union, this is the kind of road with most people killed 54,3% in 2015, more than inside urban area 36.8%.[41] However such number might change country by country.