Why there are accidents? This artful profile
At each road the person. If to depart from the road far away and to look at it sideways, it is possible to see its profile, in this case longitudinal . At main roads he is smooth, reserved and full of noble tranquility. In a longitudinal profile of roads of the lowest categories a lot of insidiousness is concealed …
Ideally the longitudinal profile is a straight line. But even on plains and in steppes there are rivers, streams and big ravines. If the road belongs to the first three categories, through such obstacles build long bridges from edge to edge of coastal heights. And if the road small, arrange descents to floodplains of the rivers, lowlands and hollows.
Here the road of the IV category crosses the small small river. Let`s peer into a longitudinal profile once again. The flat horizontal line of the road smoothly passes into the inclined line of descent, then the line of descent also smoothly passes into the horizontal line going on a lowland bottom. Here the humpbacked bridge through the small river, further smooth transition to rise, and, at last, the line of rise passes into the horizontal line to heights of the opposite coast.
All these smooth transitions between straight lines no other than parts of circles - convex where descents, and bent - below begin, at a lowland bottom. And from article about turn radius we already know that at the movement on a circle on bodies, in this case the car with all its contents, works centrifugal force.
Underestimation of this force sometimes leads to serious consequences. Here an example of accident - the real ball of manifestations of disorder of all its participants and not only them.
At winter night on the road of the IV category the car went. On descent to the lowland the driver late noticed small snow drifts, the car crashed into them and was tumbled down on one side in a snowdrift on a roadside. The following car approached and stopped on the road. From there the driver and passengers got out and began to help to install the car in vertical position.
At this time on the way to the speed of 130 km/h the Japanese SUV operated by the woman on the late term of pregnancy rushed. Meters in 30 from the beginning of descent she saw in the bottom of people and the car, pressed on a pedal of a brake and turned a wheel. The car almost did not react. The uncontrollable SUV crashed into group of people. Business was in a taiga, to the nearest hospital of 120 km, a frost - 20. Fortunately, all survived.
Even on a plain snow surface with coupling coefficient 0,25 this SUV would stop only through 260 m
But when the driver pressed a brake pedal, the car moved on the curve connecting an equal site of the road to descent which circle radius in this case made about 300 m. Centrifugal force reduced both the weight of the car and efficiency of braking almost twice.
Further the car began to move on a bias the steepness of 12% that also almost increased a brake way … twice
Many believe that it is rather safe to move at great speed up a bias. But only not at rise top!
Here the young man decided to brag to girlfriends power of the car. Having jerked in a steep slope, it did not consider that curve circle radius at top makes only about 100 m. There were to disperse about 115 km/h enough, and wheels came off the road! At top the road does small turn, and the car flew by directly - in ten-meter break. Fortunately, all survived.
Similar cases happen also on above-mentioned humpbacked bridges.
By the existing standards it is established that the minimum radius of convex curves on roads of the IV category makes 1000 m.
Therefore, dear autousers, you are not angry when road builders instead of just asphalting the local road, begin to dig something. It they make presentable a road profile. And in language of experts - in a standard state.
And, please, overcome yourself, do not continue to press frenziedly on the accelerator pedal, having curtailed from the highway on the country road even if it is equal.
And then you will survive on roads Nova Moskvy.