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MEASURES TO INCREASE THE SAFETY MOVEMENTS WHILE CLIMBING AND GOING DOWN ON THE MOUNTAIN ROADS
Eshanbabaev Abror Arslanovich, Namangan engineering-pedagogical institute,
Uzbekistan, Namangan
E-mail: abror 1966@mail.ru
Аннотация. В статье проанализирован ряд мероприятий для обеспечения безопасности движения транспортного средства на спусках и подъемах горных дорог.
Ключевые слова: дорожно-транспортных происшествий, подъем, спуск, аварийный съезд, торможение, автомобильных дорог, ограниченной видимости, обгон, продольных уклон, земляного полотна, крутых спуск, скорость на спусках, продольных уклона, кривых малых радиусов.
Abstract. A number of measures for maintaining of safe traffic of transport means on the lower parts of mountain regions, have been analysed in this article.
Key words: traffic accidents, lifting, lowering, emergency exit, braking, roads, reduced visibility, overtaking, longitudinal slope, subgrade, steep descent, the speed on the slopes, longitudinal slope, small radius curves.
Lots of ups and downs on the roads are characterized by a large number of road traffic accidents (RTA). According to the survey, conducted at the pass "Kamchik dovoni", in a mountainous area, on a plot with ups and downs, about 10-20% of the total number of reported incidents on the road happens at A-373 "Tashkent - Andijan -Osh";
The main causes of road accidents on steep ascents and descents most often due
to:
- excessive speed, developed by individual drivers downhill;
- collision with oncoming car when passing the remaining-hovering cars or overtaking trucks, significantly decreasing speed on the rise.
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The number of accidents are more when driving downhill compared to when driving on the rise, and the difference in traffic on the ascent and descent is beginning to affect even at low longitudinal slopes. The great danger of the motion on the trigger than to rise, associated with the increase in the length of the braking distance on descents, if necessary, emergency braking, and the most important - to cases of brake failure, is more than 20% of the total number of accidents caused by vehicle faults. On steep downhill, where the brakes are used intensively, this percentage is significantly higher [1].
Terms of traffic on the mountain roads are very different from the traffic conditions in the hilly and flat terrain. In a long distance route, it is necessary to carry the motion in the lower gears.
Wearing of tyre on mountain roads several times more severe than norm. The reasons for this - the impact of tire slip while passing small radius curves, overloaded wheels on protracted climbs and downs due to the redistribution of load between the axles, frequent and prolonged braking on descents.
Motion Studies modes on mountain roads showed the presence of especially sudden changes in the velocity of vehicles moving in the direction of descent. At the same time due to the exit into oncoming traffic, speed are slightly higher on the curves of small radius than estimated. This situation is typical for roads with relatively low traffic. Lots of descents are very dangerous when cars brake failure. According GBDD, major incidents of a malfunction of cars caused by brake failure.
On the downhill, we should include so-called "emergency congresses", designed to gradually stop the vehicle in which the brake system has deteriorated. Emergency congresses can be of two types:
- gravitational-braking achieved by the movement on the rise.
- retarding braking achieved by high-resistance of motion.
Emergency Congress of gravity is adjacent to the road going to lift a dead end, when driving the costs of which the kinetic energy of the vehicle sliding down a slope. At the end of the impasse, it has been arranged an area with high rolling resistance of the plowed soil berm or gravel backfill (fig.1) [1].
Favorable portions of the relief are used to devise emergency Congresses.
Emergency congresses delayed-type suit-linking in the absence of recovery, following the descent, as well as the curves of small radius in which there is a danger of the vehicle leaving the road. Braking is created by plowing the soil gradually increasing depth or Coating layer of light expanded clay gravel or sand, supported in a loose state periodic plowing.
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190-300 ^ 15 Подъем
-_ E0 100_ Ж-300 0 15
Рнс. 6.14. Схема устройства аварийных съездов с дороги:
а к б — план; в — продольный профиль: / — аварийный съезд: 2 — песчаный вал
Fig. 1 Scheme to design the emergency exits from the roads: а и б - plan; в- surface
curve; 1- emergency exit; 2- sandy shaft
When the sand be becomes hard after being wet and the wheels are no longer there to reconcile after heavy rains, you must provide a layer of sand and water to loosen it.
On long downhill gradients of more than 40-50%0, engine braking when driving down a gear is combined with the use of wheel brakes. Safety considerations preclude the movement of the slope off to the gearbox. However, observations show that the majority of vehicles in downhill speed is approximately 2 times higher than when driving uphill slope.
The car with the spoiled brakes when driving on Congress, faces great resistance and the movement gradually decelerates. Emergency congresses are especially effective in areas where after the long steep slopes small radius curves are located [2].
The entrance to the emergency exit must be indicated by pointers showing why it is used and the road sign for the entrance to the emergency should be set to prevent the possibility of its use for riding park.
Additional bands are needed on the slopes at intensive movement over 6000 aut. / Day and the length of a descent of 700 m. The need for additional devices on the downhill lanes depends on significant difference in the speed of the different types of cars, the magnitude of the slope, length of descent and road conditions at the end of
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the descent.
As shown by many studies, with slopes of up to 20-25%0, shutter length does not affect the rate of speed increase which does not exceed 5-10%. Under the deviations of 25-45%0, their rate stops to affect the speed of the movement and the nature of the change in in length of descent is defined by stretching and road conditions at the end of down. On the downhill speed increase occurs slowly at first, and only 700m away from the start of the descent it reaches maximum value [3].
If after the length of 700-800m descent, the ascent begins, drivers tend to create an additional supply of kinetic energy during movement on descent and increase the vehicle speed rate to about 10%.
The presence in the large end of the descent of the bridge, or narrowing of the carriageway small radius curve movement causes reduction rate of 20-30%. Even curves of radius 2,000 m or a small bridge with a width of the roadway at the end of the shutter cause the driver to reduce speed by about 10%.
Changes in the speed related to the road conditions in the end of the downs also begins to affect the distance 600-700m. from the end of the descent. With slopes over 45%, the speed of the movement rises, and at 50-60%0, the increase reaches 25%.
Parameters of additional lanes on the descents are made the same as that for the bands on the rise. These bands also work effectively only when applied markings on the carriageway and setting characters [4].
On long climbs with longitudinal slopes greater than 60%o, we should provide site place for vehicles to stop in the form of horizontal sections or sections with a longitudinal gradient of not more than 20%o, minimum length of 50 m, designed for at least 3-5 trucks, with these sites, or sites by 1.5-2.5 km. at altitudes above sea level 1000 m. and through the 1.1-1.5 km. at altitudes of 4000 m [5].
Subgrade in this area should be broadened so that stopped cars does not interfere with the movements.
All of these circumstances deserve ensuring safety on descents, climbs on the mountain roads of the republic and considers the designing and producing vehicles intended for use in the mountains.
Literature:
1. V.F. Babkov. Road conditions and traffic safety. M. "Transport", 1982. - 288 p.
2. V.F. Babkov. Car roads. M: "Transport", 1983, 280c.
3. V.F. Babkov, V.F. Davochkin et al., "Road conditions and traffic." M: "Transport" 1994. 240.
4. R. Elvik, A.B. Leyusen, T. Vaa. "Handbook of Road Safety" / Per. s NOK. Edited by prof. V.V. Silyanova / M: MADI (STU) 2001 754.
5. SNIP Highways KMK 2.05.02-95 Republic of Uzbekistan. Tashkent. 1996. - 66 pp.
