Carriageway
The road section describes the vertical section of a road perpendicular to the road axis. It includes the traffic space and the necessary security clearances. Furthermore, in the road cross-section, for example Banquet ( see below), contain drainage facilities, embankments and verges.
A basic distinction is between urban and extra-urban cross-sections because the components and the requirements are different. The design of the road cross-section depends on traffic-related, physical and economic requirements and political circumstances and the setting of the competent authority.
The regulations contain standard designs for road cross-sections, which can be used in the design and construction of roads. This rule cross sections represent standard dimensions and are suitable for different traffic densities and encounter cases (see guidelines for the construction of roads - cross section).
The expansion of cross-section is one of the draft documents for road construction. It shows the structure of the bank and the drainage facilities of the planned road.
- 6.1 superstructure
- 6.2 substructure
- 6.3 Substrate
History
The development history of the street has spawned a variety of different road sections. The geometry of the road cross-section always subject to the requirements of each epoch and the actual use ( as a back alley house development, access road, Avenue, Market Street, Army avenue, highway, etc.).
Among the first permanent paved roads in Europe include the Roman roads. Their cross-section depended on the transport needs of the time. In the middle of the Roman road a paved track was arranged that allowed a uni-directional or bi-directional traffic, depending on the width. At the edge of the track riding trails were formed.
Basic dimensions
The width of a road or whose cross-section is based on basic measurements, compliance with a safe and functional traffic flow are essential. Depending on the network (just motor vehicle, pedestrian or cyclist ) are different values. You must be complied with for each road category. Only in very limited space or low traffic speed (about traffic-calmed area) can be deviated from the basic measurements. However, so-called " austerity cross sections ," or narrow sized road cross sections slow the flow of traffic, can lead to increased, but also lowered risk of an accident policy. But make the long term a satisfactory state of development dar.
For these reasons, road cross sections contain defined basic dimensions that are laid down in laws and regulations. In Germany, for example, by the maximum permissible vehicle dimensions in the road traffic licensing regulations (short traffic regulations ). The basic measurement consists of the basic vehicle dimensions and the range of motion. The latter is necessary, since in this range steering and driving inaccuracies can be compensated. The width of the movement range is dependent on the traffic speed, traffic volume and traffic composition. The sum of the dimensions of the vehicle and range of motion is called traffic area. The gauge is obtained if additionally the security space is added to the transport area. The gauge is a road for the purpose of navigability always kept free.
If the adjacent lane oncoming traffic is passed, also a two-way traffic surcharge is to be considered to ensure a safe distance. In the context of European harmonization of road transport is the maximum width of a vehicle 2.55 m (in special cases 2.60 m ) and a height of 4.00 m ( 4.50 m clear space ). For cyclists, traffic space width of 0.60 m is considered, with pedestrians 0.75 m. Motorway - usually three-wheel - but bicycles, bicycle trailers (eg for 2 children next to each other ) and some load wheels are much wider. For all two-wheeled vehicles is considered that their driving line something commutes particularly at slow speed and they are at an angle when cornering, so need more horizontal space.
Components
The road cross section is made up of different components. From their combination gives rise to the requirements of adapted road cross-section. Subsequently, all of the components and their meanings.
Roadway
The road serves as a transport space and is composed of the individual lanes and the edge strips. You must be traveled by vehicles and forms the coherent, fixed part of the road. The side strips are not part of the roadway. To illustrate the orientation and traffic management in road transport, road markings are applied to the roadway.
A road may consist of multiple lanes, which may in turn comprise a plurality of lanes. Motorways and similar federal highways are equipped with so-called two carriageways, each with multiple lanes and side stripes. The road users against running track is also called the opposite lane. The two carriageways are ( for example, a median strip with guardrail ) separated by a structural device. By this measure to safety, especially on roads with high travel speed increased and the risk of glare is reduced by oncoming traffic.
Within the roadway track body can be recessed for rail vehicles. In addition to the roadway is located within towns and cities often an elevated pedestrian walkway or sidewalk, sometimes a bike path. If a bicycle lane is marked, this does not belong in Germany with the road. This is true even if the bike lane is part of the asphalt surface of the road. Protection strips, however, are part of the roadway. In Austria, the bike lane is a specific for bicycle traffic and specially marked portion of the road.
As a fortified part of the road is the road of a single- or multi-layered road pavement. On a bituminous or hydraulic base course is the top layer ( also pavement ). The layer thickness and the grain size of the material increases from the lower layer to the upper layer back on. For use as a cover layer are essentially of asphalt and concrete in question. However, plaster or plate coverings are possible. Composition and thickness of all layers involved are determined by the traffic load and the design-relevant stress ( equivalent 10 -t - Achsübergänge ).
The surface condition of the road critically influenced various phenomena when driving. Through them, the noise generated by the tire rolling noise and reflection of sound. In a wet road is slipping and the risk of aquaplaning. In winter, the road surface may freeze, it is important to note that uneven deposits are more difficult to get rid of snow as flat.
Traffic-calmed areas legally dispose of any roadway, sidewalks and bike paths, but only via a special area. This is often equipped with pavements. Thus, the speed of traffic can be reduced and the quality of stay of a road to be improved. In residential streets pedestrian areas or also artificial bumps or increases in the road surface ( so-called Teilaufpflasterungen ) can be installed to reduce the speed of vehicles.
With very wide street cross sections, the road surface may be divided into the main road and in one or more secondary roadways. The main road is the flowing, passing through traffic. The side roads, however, take over the development of the surrounding land, which are separated by separator strip to wide green strip with pedestrian and / or bicycle paths of the parallel run main road.
Lane
The lanes ( also fachsprachlich actually outdated, called lane ) indicates the area that is a vehicle for the trip in one direction available. The width is determined from the basic lane width and a possibly to be applied in oncoming traffic surcharge. It represents the space available, which requires a one-or multi-track vehicle for unhindered driving on. The width of lanes varies between 2.75 m and 3.75 m and depends on the design speed and the available space. In areas of construction sites or in pedestrianized areas smaller widths may be possible.
The use of lanes is controlled, for example, in Germany in § 7 Highway Code. There, the application of the law driving commandment of the traffic density is conditional and concretized the zipper method and described the procedure for a lane change.
The lane is usually marked by road markings, such as road boundary and lane boundary or guideline. However, several lanes must not be marked mandatory. The width of the road is too low, the label is omitted lane.
The 4-0 system is for temporarily blocking the lanes in each direction. Here, a direction is completely eliminated. A special form of the lane is the additional lanes. It is located on uphill grades and at the junction area. In the area of jobs the so-called Behelfsfahrstreifen is established. It is a lane with reduced width, which is displayed by means of appropriate labeling.
Edge strips
The edge strip marks the end of the road and prevented from breaking the pavement edge. In inner-city area of the edge strip is replaced by a drainage channel with curb. On the road out of town close to the banquet. It must therefore be clearly defined at the track alignment ( and previously the configuration) of roads.
The control of the works or the controlled guidance of Construction can be done:
- Through the course of the road axis and road width by successive coordinate pairs (or triples ), or
- As coordinative course of roadsides itself, or
- By digital alignment design.
The Stakeout ( transfer of planning in nature ) is the task of geodesics or an experienced foreman. However, the inventory ( after construction ), its implementation in the cadastre and monitoring of any settlement is solely responsible for the surveyor. The basis of this survey are the roadsides, which are measured on location and on the level at a distance of several meters to tens of meters. These shorter arcs or transition curves are defined and as " arc start ", and ( in most cases arc center ) added, " bow end."
For longer being off road are the roadsides by weathering, often difficult to exclude the growth of the sward and the grit or they extend several inches below ground. This itself is a common problem for the survey because the fixed points are only expose, but the reference points of the point descriptions are often the previous roadsides.
Separator strips
With the help of the release strip which is characterized by the disruption of asphalt, roadways or lanes are separated. It is to distinguish between the central strip and the side of the parting strip. Find a greening of the parting strip instead, one also speaks of a green stripe.
The center strip is located between two carriageways and serves the separation of traffic. He is in Germany at highways and four-lane automobile roads usually 4.0 meters wide. Even with limited availability of land, he is at least 2.5 meters wide. It is provided with a guardrail or concrete barrier. In order to reduce the glare from oncoming traffic, often there will be a planting. At regular intervals he is paved to direct the traffic on the other carriageway in the case of the establishment of construction sites ( median strip crossing ). In the area of highway Behelfsflugplätzen it is secured continuously. Partly can be found on motorway sections with wide median strip. These are usually applied to take account of future construction projects.
When highways in mountainous areas is sometimes in the middle strip a large difference in altitude because the carriageways are on different gradients. If the carriageways performed on separate lines (eg Albaufstieg motorway A 8) we no longer speak of a central strip.
2008 it was announced in Switzerland that the shrubbery is cleared and paved in median strip on Swiss motorways. The reason for this is the one part is no longer necessary thanks to better headlights visor protection and on the other hand, the maintenance of shrubbery had become dangerous due to the increasing traffic. In addition, costs can be saved as.
In the urban area, it is possible to set up on the median strip of the track body of the tram. So tracks are laid for underground or light rail, in Essen next to the U-Bahn also a Spurbusstrecke in some city highways and urban expressways on the median strip. Here, the access is done to possibly located on the central reservation stations across pedestrian crossings and underpasses.
On the green strips or side parting strips are similar to the banquet next to the roadside vegetation (such as trees, shrubs, turf ) and structural mechanisms of road equipment. It serves as a separating strip between the vehicle traffic and the wheel or pavement. The width of the green strip is optimal when the vegetable room is sufficient for the roots is available. The green and wood care is taken by the competent road maintenance is carried out regularly, or community and to optimize the clearance profile and visibility.
Shoulder
The side strips ( in Austria and Switzerland also Abstellstreifen ) is located next to the road and is separated by a solid line. In Germany, the side strips are not part of the roadway. It may be used only by bicycles, interurban addition of agricultural train and work machines, carts and similar slow vehicles. Also a use is permitted in order to allow other vehicles to overtake. This does not apply to highways.
The side panels may be secured or unsecured. It is necessary to distinguish between the hard shoulder and park strips.
A hard shoulder ( in Austria and Switzerland emergency lane ), erroneously called " emergency lane " or " emergency lane " is used primarily to stop a motor vehicle in an emergency without the traffic flow is impaired. It is mainly configured on motorways and similar federal roads with carriageways. Absence of such an emergency lane, a broken-down vehicle can be the cause for the collapse of the traffic flow (congestion ) or for an accident.
In addition to the above-mentioned function of the hard shoulder can also be used for avoidance of obstacles, for traffic management at construction sites than tramlining in accidents, as a work space for the operation of services or as a way for the emergency services. Especially in tunnels increased a hard shoulder safety considerably. The side panels can be navigated in Germany, Austria and Switzerland in no case, unless he is expressly authorized by appropriate signs (such as A99 ) enabled. Thus, between the permanent and the temporary status of distinguished stripes. The temporary emergency lane can appropriate light signals or traffic signs on as needed, usually in heavy traffic, be opened to traffic. This measure is intended to ensure that improved the traffic flow of a congested road section. Both camera systems monitor the traffic flow and the traffic situation.
The release of the side panel is only when all conditions are met:
The risk of accidents on highways without a hard shoulder is higher by up to 30 %. If there is no hard shoulder is available, emergency stopping bays must be established in order to reduce the danger of a collision with breakdowns at regular intervals.
The side stripes takes in both inner-city function as a parking lane. In this case, vehicles can be permanently parked next to the roadway. Depending on the type of vehicle lineup is the park strips of different widths to be dimensioned.
Banquet
The Banquet ( also the banquets ) is located at the outer edge of the road crown, connecting to the margins or, if present, on the side strips. In contrast to the summer trail banquets are usually arranged on both sides of the paved roadway. The banquet serves as a soft verges and can accommodate facilities of road equipment ( such as traffic signs or guardrails ). There is also the paved roadway additional support and can seep a portion of the surface water. For the driver the banquet the road is bordered by its color and material contrast from clear and so facilitates orientation in the traffic area. Built-up areas are located, with the exception of cultivation independent city streets no banquets, because there is a walkway connects normally to the edge strips.
The rule width of the banquet is 1.5 m, this dimension can be changed due to special features (narrow lane or location in the incision ). The ignitor is mounted, for example, a light gravel or crushed stone layer is applied on the upper floor. An excessive topsoil order has lush vegetation result, thereby increasing the problems of maintenance. Meanwhile gone over to form a thin gravel and grass, which is still sufficient for this purpose was clear.
At the banquet a motor vehicle may be parked ( for example, in the case of a breakdown ) without the traffic flow is significantly affected. Pedestrians who are staying at the banquet in order to achieve approximately a Notrufsäule are not forced to go to the edge strip.
Walking and cycling
At the edge of the road there is the possibility to form a walking and bike path. A combination of pedestrian and cycle is often standard practice, in this case, however, there may be conflict between the two types of traffic.
The width of the footpaths or cycle path depends on the amount of pedestrians and cyclists. Towns or cities can also be dependent on the geometry of the existing space or urban design measures. Out of town the road by walking or bike path is to move away by a side parting strip to allow a safe use.
Embankment
If, between banquet and the terrain height difference, so an embankment is formed at the edge of the road cross-section. If the banquet underneath the property is called a cutting slope, the banquet, however, is above the terrain it is given the name embankment slope. A bleed is where the road body cuts the mountain side into the terrain and is piled up on the valley side. The slope of the embankment must meet erdstatischen requirements that generally slope is 1: 1.5 larger for embankment heights 2.0 m. If the slope height less than 2.0 m as the slope with a width of 3.0 m is to be formed.
The rule inclination may be waived if special requirements are placed on the embankment. This can happen, for example, fitting into the landscape, based on immission or to avoid snow drifts. At the intersection between the slope and the terrain profile of the kink is rounded.
At high embankments, the system of berms ( paragraphs ) to improve stability and to facilitate the conversation may be necessary practical or safety reasons. Dewatering wells, which are necessary for the road drainage optionally be arranged at the toe of the slope. When planting the embankment is to ensure that the maintenance effort does not rise too much and the loading gauge is permanently free. This can be achieved by a sufficient distance of the road from the road surface fouling.
Requirements
The cross section of a road is to be selected from a transport planning perspective so that the forthcoming traffic load can be safely and reliably complete and adequate transport quality is guaranteed. The interests of the economy (construction and maintenance costs ) and environmental protection as well as persons affected local residents are to be observed (noise, pollution ). From an urban planning point of view of the road cross section serves as a recreation area and shall meet such requirements.
Bank
In the contemplation of the cross section in addition to the individual components of the bank of the road and footpaths and cycle paths can be seen. A distinction is made between the two bank forms Einseitneigung and roof slope form. The cross slope of the roadway is used for road drainage and results together with the longitudinal tilt ( if any) the inclined slope of the road. Missing bank produces water surfaces on the road, which can increase the risk of aquaplaning or contribute to ice formation. Two-lane rural roads are equipped with a Einseitsneigung, whereas usually the roof profile is to be found in urban areas. Minimum cross slope is 2.5%, this value can be increased on uneven road surfaces ( pavement ). In ZTL areas is often another profile shape to be found, in which the two halves of the paved surface are inclined toward the center, and there runs a gutter.
Road body
The road body is considered as a whole not just from individual cross-sectional elements, but is divided in its structure in different layers. Basically here is to distinguish between the concepts underground, substructure and superstructure.
Superstructure
The superstructure comprises all the layers that are structurally necessary to ensure the sustainability of traffic area. Of the superstructure is usually only see the top layer ( asphalt, concrete, pavers, slabs ). The entire superstructure but consists of several layers of different materials. The superstructure of a roadway has a total thickness of 40-90 cm as a rule. For walking and cycling routes, the total thickness is usually 20 - 40 cm. The sequence and thickness of the individual layers of the superstructure is in Germany by the Guidelines for the standardization of the superstructure of traffic areas ( RStO 12) or controlled by the requirements of the local road authorities. In Switzerland, the structure through various SN and the VSS (Swiss Association of Road and Transportation Experts ), and cantonal / local rules is given. In Austria, the structure is in the guidelines and regulations for the Highway (including RVS 08.03.63 ) Research Road - Rail - Transport ( FSV ) determined.
Substructure
As a substructure of the artificially created earth body between superstructure and base is called, which is primarily necessary to achieve the level of the road ( embankments or similar). For the substructure, the same requirements apply to the carrying capacity as for the underground.
Underground
The underground is the pending below the superstructure or the substructure soil or rock. On the ground there are certain requirements about the sustainability in road construction. Usually a deformation modulus (EV2 ) value of at least 45 MN/m2 should be achieved. If this value is not reached, the load capacity can be improved by replacing the soil, soil stabilization or the laying of geogrid and nonwoven fabrics.