Current situation
The territory of the designed sports and leisure center is located in Istra Municipal area Moscow region between the villages of Leonovo and Kartsevo. Transport connection of the territory of the planned location of the sports and leisure center with villages and cities Istrinsky district carried out along the Volokolamskoye Highway – Buzharovo – Savelyevo – Rumyantsevo highway.
Highways
The Volokolamskoye Highway – Buzharovo – Savelyevo – Rumyantsevo highway is a regional road III values technical category. In the area under consideration, the width of the carriageway is 6 m. Road markings are applied to the carriageway. The markings have two lanes for traffic. vehicles in both directions. Artificial lighting There is no highway on the section of the road under consideration.
Project proposals
Project proposals for transport services for the territory of a sports and leisure center are developed with the aim of streamlining and ensuring the safe movement of vehicles and pedestrians, for the purpose of their transport services and determining the location of parking lots.
Roads and streets
External transport connections of the territory under consideration will be carried out along the regional highway “Volokolamskoye Highway – Buzharovo – Savelyevo – Rumyantsevo”.
The project provides for two planned streets local significance, for the passage of motor vehicles to the territory of the sports and leisure center. Entry and exit to the territory of the sports and leisure center is carried out from the planned local street located to the north of the territory in question. Access to the Volokolamskoe Highway – Buzharovo – Savelyevo – Rumyantsevo highway is carried out along the planned local street located to the west of the territory of the sports and leisure center.
The project provides for the reconstruction of the Volokolamskoye Highway - Buzharovo - Savelyevo - Rumyantsevo highway, maintaining two lanes and increasing the roadway to 7.00 m. It also provides for the construction of 2.50 m shoulders on each side of the road (0.50 m reinforced lane curbs on each side of the road). The width of the carriageway of the streets is taken to be 8.00 m (4.00 m is the width of the traffic lane in each direction, taking into account the passage of horse carriages along it). The planned transverse profiles of streets and highways are presented on the sheet “Scheme of organization of the road network and traffic flow” (profiles 1-1, 2-2, 3-3).
Expressway lanes have been installed along the highway in the area where local streets adjoin it. Exit from the planned street to the highway is carried out in both directions of the road. The parameters of transitional express lanes and radii of the junction curves of the highway and the planned street are adopted in accordance with SNiP 2.05.02-85 “Highway Roads” and can subsequently be clarified in accordance with the technical specifications of the State Institution MO “UAD MO “Mosavtodor”.
It is planned to apply appropriate road markings along the highway and streets and install appropriate road signs in compliance with GOST R 52289-2004 “ Technical means organizations traffic. Rules for the use of road signs, markings, traffic lights, road barriers and guide devices", GOST R 51256-99 "Road markings. General technical specifications" and GOST R 52290-2004 "Road signs. General technical conditions".
Network of internal passages
The departure of vehicles from the territory of the sports and recreation complex is carried out in the checkpoint area on the street located north of the territory in question. Departure is carried out in both directions of the street. The driveway provides access to the administrative building and a parking lot for 13 cars. To the east of the junction of the driveway with the street, there is an entrance and exit to an open-air parking lot designed for 68 cars. The minimum width of driveways is 8.00 m. The radius of curvature of the roadways of driveways at junctions with the street is 8.00 m.
Driveways are accepted with the installation of asphalt concrete pavement, closed rainwater drainage and installation curb stone. At night, it is proposed to illuminate the entire designed internal network of passages using lamps installed on special masts.
Traffic at junctions between driveways and streets is regulated road signs and road markings.
Structures and devices for temporary storage of vehicles
The maximum one-time estimated number of visitors to the sports and recreation complex is 300 people. The number of permanent employees is 12 people, temporary – 30 people. Thus, in accordance with TSN 30-303-2000 “Planning and development of urban and rural settlements. Moscow region" the maximum estimated fleet of cars will be 95 units. For visitors it is necessary to provide 90 parking spaces at the rate of 30 parking spaces per 100 people. For employees, 5 parking spaces at the rate of 15 parking spaces per 100 employees.
In the area of the administrative building there is an open parking lot for 13 cars. The open-air parking lot, located east of the main entrance, has a capacity of 66 cars and has a separate entrance from the street. Also along the local street there are parking spaces adjacent to the roadway for 16 cars.
Thus, the total capacity of open parking lots in the territory under consideration is 95 parking spaces.
Public transport
It is planned to place a stop along the Volokolamskoye Highway – Buzharovo – Savelyevo – Rumyantsevo highway public transport south of the territory sports and leisure center 400 m away.
Pedestrian traffic
Pedestrian movement is planned to be organized along sidewalks along the highway, streets and driveways. Places where pedestrian and traffic flows intersect are equipped with pedestrian crossings (with appropriate road markings and appropriate road signs).
Along the Volokolamskoye Highway – Buzharovo – Savelyevo – Rumyantsevo highway there is a 1.50 m wide sidewalk on the side of the sports and leisure center. The sidewalk also connects the area in question with a public transport stop. Along the planned local street, located to the west of the sports and leisure center, sidewalks 1.50 m wide are provided on both sides of the roadway. Along the planned street of local importance, passing from the north of the territory under consideration, a sidewalk with a width of 3.00 m is provided with north side from the roadway. On the eastern side of the sports and leisure center there is a 3.00 m wide sidewalk connecting the sidewalks of the highway and the planned local street.
Traffic through the territory of the sports and leisure center is planned to be organized along sidewalks and pedestrian paths 1.5-3 m wide; pedestrian movement is also allowed along the roadway.
The basis of the city's road network - the main street and road network - consists of main streets, squares and roads of the city and regional significance, through which the movement of public and all other types of transport is carried out, connecting residential and industrial areas of the city with each other and with citywide and zonal centers, with citywide administrative, public, cultural, shopping and sports facilities, as well as with recreation areas, parks and facilities external road transport (river ports, airports)
The road network develops gradually as the city grows. In old cities, as a rule, the road network was created over several centuries and its basis was the directions of country roads that at one time connected the settlement with the outside world.
The design of the main road network is inextricably linked with the design of the city master plan, both when creating new cities or new districts, and when reconstructing old cities. Obviously the most rational decisions can be obtained when designing new cities.
When developing master plans for the reconstruction of old cities, it is often necessary to change the directions of existing street directions, lay new streets, create streets along duplicate directions, and at the same time carry out reconstruction, and often demolition of adjacent buildings.
In the process of designing new areas of large cities, it is necessary to combine techniques for developing vacant areas with reconstruction methods. In all cases, when designing the main road network and master plan, it is necessary to be guided by a set of requirements, the basis of which is minimizing passenger and cargo transportation. This is achieved by correct functional zoning of urban areas, providing convenience and the least amount of time spent on all types of transport connections and, first of all, on movement from residential areas to places of employment, to cultural and public service enterprises, to the central core of the city and to the centers of planning zones and within urban transit traffic through the city center.
In this case, it is necessary to provide:
Placement of the main city-forming points, taking into account the minimum load of the street network with freight traffic by creating freight roads outside the central and residential areas of the city and such construction of the road network that will provide the necessary throughput of highways and transport hubs and the division of flows by high-speed traffic and by mode of transport;
Tracing main highways along shortest distances between cargo-generating and passenger-generating points.
In addition, the planning solution for the road network should provide high level safety of traffic and pedestrians, greening of streets and maximum reduction of the negative impact of transport on environment, expedient construction of a system of urban route transport, the possibility of redistributing traffic flows in the event of temporary difficulties in in certain directions or their sections, as well as laying engineering underground and above-ground networks and structures.
The planning scheme of the road network can have any shape, but it is very important that its construction is clear and simple, not allowing mutual overlap of traffic flows due to the merging of various highways in individual sections, so that it contributes to the distribution of traffic flows and meets all the set of requirements placed on it.
The following types of road network planning schemes are distinguished: radial, radial-ring, rectangular, rectangular-diagonal, triangular, combined and free.
Radial scheme - most often found in old cities, which were formed at the intersection of external roads and developed in the direction of connections with other cities by country roads. With this scheme, communication between city districts and centers is well ensured, but overload of the central part of the city is inevitable and communication between districts is difficult. This scheme does not meet the requirements for a modern city transport system.
Radial-ring - the scheme is a radial scheme with the addition of ring highways, the number of which depends on the size of the city, and the location is determined by transport correspondence and local conditions. Ring highways remove significant traffic load from the central part of the city and create convenient connections between districts, bypassing the central city core. An example of a radial-ring system is the Moscow road network. In large and major cities there may be several radial-ring areas around the centers of the city's planning zones. This scheme is called multifocal.
Rectangular layout - is a system of mutually parallel and perpendicular streets. It is usually found in relatively young cities, the construction of which was carried out according to pre-developed plans. The advantages of such a scheme include its simplicity, high throughput, the possibility of dispersing transport parallel to streets, the absence of a single transport hub. The disadvantage of the rectangular scheme is the significant lengthening of the paths connecting diagonally opposite blocks and districts of the city.
Rectangular-diagonal pattern - is a rectangular pattern with the addition of diagonal connections. Here the advantages of the rectangular design are preserved and its disadvantages are mitigated. Thanks to diagonal highways, connections between peripheral areas and the center are simplified. The disadvantage of the scheme is the presence of nodes with many incoming streets, including at an angle, which makes it very difficult to organize traffic flow on them and place buildings.
Triangular pattern - rare due to the formation of large number nodes with the intersection of many highways under an acute node. In some old areas of London and Paris, such a construction of the road network is found.
Combined scheme - represents various combinations of dangerous above geometric schemes. It is found quite often in large cities, where the old areas of the city have a radial-ring pattern, and the new ones have a rectangular pattern.
Free scheme - the road network does not contain elements of the schemes described above. It is found in spontaneously developing Asian and medieval European cities. This scheme is applicable in difficult terrain conditions in resort cities or recreation areas.
For the technical and economic assessment of the road network, the following indicators are used: density, degree of non-linearity of communication, network capacity, average distance of city districts from each other, residential areas from the main places of employment from the city center or other important centers of gravity of all types of transport and pedestrians, the degree of loading by transit flows of the central transport hub, the configuration of the intersection of main streets.
The density of the road network is the ratio of the total length of streets in km to the corresponding area of the city and its region in km2.
IN general view the density of the road network l km(km)2 will be equal to:
where, ?L is the sum of the lengths of streets and roads, km. When determining the density of the main road network? L represents the length of only main streets of both citywide and regional significance;
F is the area of the city served by the sum of the lengths of streets and roads, km2.
At high density main network of streets and roads of a city or its region, short pedestrian approaches are reached, or, as is commonly called, approaches within walking distance to public transport stops. However, this leads to frequent crossings of main streets, which reduces the speed of communication.
The Building Codes and Regulations adopted in our country (Part 2. Design Standards, Chapter 60 “Planning and Development of Cities, Towns and Rural Settlements”, referred to for brevity and subsequent presentation as SN and P 11-60-75*), normalize average density main road network 2.2 - 2.4 km/km2.
In the central districts of the city, the density of the road network can be increased to 3.5-4 km/km2, and in peripheral areas reduced to 1.5-2 km/km2, but not less than the density at which the walking distance to the nearest stop public transport does not exceed 500 m (including the length of the pedestrian path through the territory of the microdistrict) and is reduced to 300 m in climatic subregions IA, IB, IIA, and to 400 m in climatic region IV.
The degree of non-straightness of the road network is determined by the ratio of the sum of the distances between the main points of the city along the street network to the sum of the distances between the same points along straight air lines. To characterize this indicator, the coefficient of non-linearity is used.
where, ?Lф - the sum of the actual distances between the main points of the city, measured along the entire network of main streets; ?Lв - the sum of distances between the same points, measured along straight air lines.
A more comprehensive description of the degree of non-linearity of the city’s road network is obtained taking into account the average distances.
The average practical distance is determined by the formula:
L f. Wed =?L f /n
Where, n is the number of correspondences (i.e., the number of pairs of points between which the average distance is measured); =?Lф - the sum of the actual distances between these points, measured along the road network.
The average distance between these pacts, measured along overhead lines, will be equal to:
Lv.sr = ?Lv/n
Taking into account the average distance, the non-straightness coefficient is determined from the expression:
l = L f. Wed / L w.wed
To evaluate the road network based on the coefficient of non-straightness, you should use the following data proposed by A. E. Stramentov:
Table
It is recommended to design road networks with a degree of non-straightness from very low to high. At very high and exceptional high values it is necessary to reduce non-linearity by compacting the road network, straightening individual important areas, introducing diagonal directions.
The radial-ring scheme of the road network has the lowest non-straightness coefficient of 1.00-1.10; with a rectangular-diagonal scheme it can fluctuate between 1.11 - 1.20, and with a rectangular scheme - from 1.25 to 1 .30
The average distance of residential areas from places of employment, from the city center or from any other mutually corresponding points is not simply defined as the average arithmetic quantity, and as a weighted environment, it is treated taking into account the population size in certain zones of the city.
To determine the average distance between two points in the city (for example, from residential areas to industrial zone or residential areas to the city center), concentric circles are drawn on the city plan at a distance of one kilometer from each other, the average distance is determined, and the number of population in each kilometer zone is established.
The average distance is Lup km, and there will be
Lup = H n1 L n1 + H n2 L n2 +…..+ H nn L nn /H
where H n1 H n ….. H nn population of each kilometer zone
L n1 L n2 …..L nn - average distance of each kilometer zone from the considered industrial zone of the city center
N - city population
The average communication time more accurately characterizes the city's road network than the average distance, especially for large cities.
The average communication time between different points of the city is determined in the same way as the weighted average, taking into account the nature of settlement, and is found from the expression:
T up = H n1 T n1 + H n2 T n2 +…..+ H nn T nn /H
where - T n1 T n2 …..T nn average communication time to each zone min
In general, the city's road network should be designed in such a way that the total time spent on one-way travel from the place of residence to the place of work for 80-90% of the population does not exceed 40 minutes in large and major cities. This standard is also preserved for other cities where the place of employment is located at a considerable distance from residential areas, such as, for example, in hazardous conditions. sanitary requirements industry located with a large rupture zone protection. In other cities and populated areas, the communication time between residential areas and places of employment should not exceed 30 minutes.
The design of the city's planning structure, its transport systems and road network can be divided into three stages. At the first stage, the main tasks are solved - functional zoning of the urban area, placement of the most important objects, the direction of the main connections and the orientation and density of the backbone network; at the second stage - placement of objects of secondary importance and branching of the network. The main task When designing a road network, it is necessary to develop an option in which, taking into account the entire sum of various requirements, a high level of transport services for the population will be provided with minimal total capital investments in transport construction.
Transport is a special branch of material production that deals with the movement of goods and passengers. Urban transport is a set of vehicles and devices that provide cargo and passenger transportation within the city. Components of urban transport:
rolling stock, road networks and other transport corridors; buildings and structures for service and repair and maintenance of rolling stock and roads.
The UDS is formed in the form continuous system taking into account the functional purpose of streets and roads, intensive transport and pedestrian traffic.
The basis of the planning structure is the skeleton of the city - comp. main streets and roads. They are the frame and one of the few little changeable parameters of the urban planning structure.
The city's UDS includes:
- Main roads: high-speed and regulated traffic
- Main streets
A) citywide use: continuous movement and controlled movement
B) regional significance: transport-pedestrian and pedestrian-transport
- Streets and roads of local importance: a street in a residential area , streets and roads in research and production, industry. and commercial warehouse zones and areas , pedestrian streets and roads , park roads , driveways , bike paths
The road network scheme is determined by a complex of urban planning tools. The most important of them are: -compactness of the city plan; - placement of city-forming enterprises; - natural features terrain; -convenience of transport services; - compositional and aesthetic considerations.
In the city plan, streets and roads form a network of surface communication routes. Basic UDS schemes:
- rectangular-diagonal diagram;
It is a development of the rectangular design. Includes diagonal and chord streets, made through existing buildings in the most congested directions. But complex intersections with merging streets arise => the use of complex transport interchanges.
-radial-ring;
It is typical for large and major cities and contains radial (serve as a continuation of highways to connect the center and the periphery) and ring (distribution highways that ensure the transfer of transport from one radial highway to another).
-radial-semi-circular(the ring does not have to close)
-linear diagram;
-mixed;
- free
(typical of the old southern districts. The entire network consists of narrow, curved streets with variable roadway widths, often excluding car traffic. For modern cities such a scheme is unsuitable)
Such schemes are rarely found in their pure form. Within the district, a rectangular layout is maintained, and as development progresses transport system grows from radial to radial-ring.
Radial-ring
2. Engineering preparation of territories complicated by physical and geological processes.
Engineering training is engineering activities to transform, change and improve natural conditions, as well as to exclude or limit physical and geological processes, in their development and impact on the city territory. The composition of measures is established depending on the natural conditions of the developed territory (relief, soil conditions, degree of flooding, swampiness, etc.) taking into account the planning organization of the populated area.
But there are territories complicated by physical and geological processes that require a special approach.
Landslides
Landslides are movements of earth masses on slopes that occur under the influence of gravity as a result of an imbalance of earth masses. Based on the volume of earth masses that have come into motion and the depth of their capture, landslides are divided into mudslides, wasps and landslides themselves. They occur on slopes of river banks, seas, ravines and mountain slopes.
In urban and rural settlements located in areas prone to landslide processes, it is necessary to provide for the regulation of surface runoff, interception of groundwater flows, protection of the natural buttress of the landslide massif from destruction, increasing the stability of the slope by mechanical and physical-chemical means, terracing slopes, and planting green spaces.
Measures to prevent the development of landslides:
You should not stack construction and other heavy materials on the slopes and upper edges of slopes, or place monumental massive structures. When performing leveling work, you must not cut at the base of the landslide slope. large masses soil, which is a natural support (buttress).
To avoid dynamic loads and shaking of slopes, roads cannot be built for the movement of freight transport along the upper edge of the slope.
The territory of landslide slopes should be used for planting trees, shrubs and adapted for walking and recreation for the population.
With insufficient sunlight and poor ventilation of shaded slopes, snow will melt slowly in the spring, which can lead to waterlogging of the slopes. In these cases, when landscaping slopes, you should not densely plant trees and shrubs.
To protect landslide slopes from destruction, preserve vegetation on them and improve them, a number of measures are carried out aimed at eliminating the causes that contribute to the occurrence of landslides. The main ones are:
A) proper organization drainage of rain and melt water
b) a drainage device that allows you to intercept groundwater deep in the slope
c) proper operation of the sewerage network, water supply and other structures
d) carrying out bank protection works within the coastal strip of rivers, seas and other bodies of water;
e) creation of mechanical resistance in the path of movement of earth masses in the form of retaining walls, pile rows and other obstacles.
f) organization of permanent anti-landslide stations to monitor the condition of the surface of landslide slopes and the processes occurring in their depths.
ravines
Gullies appear on the soil surface as a result of the impact of water flows on loose rocks. Thawed water in spring, storm water in summer systematically destroys the surface of the soil layer.
Gullies develop within the drainage area in the direction of surface flow, i.e. from the mouth of the drainage basin to the watershed crest of the basin.
Depending on the nature of the intended use of the ravaged area, a project for its improvement is drawn up. Measures to adapt the territory for urban development are limited to preventing the growth of ravines. Shallow ravines (up to 2.2-5 m) are filled up and the resulting areas are used for urban development. In case of deep ravines, their areas are used for reservoirs (ponds), as well as for the construction of inputs for railway lines and highways with convenient intersections and interchanges located in different levels. The steep slopes of preserved ravines are smoothed and landscaped. In the upper reaches of shallow ravines it is convenient to locate buildings with basements.
Karst formations
Groundwater when meeting easily soluble rocks ( rock salt, gypsum, limestone, dolomite, etc.) dissolve and leach them. Soluble substances are carried away along with water. As a result of this, in the thickness earth's crust cracks, wells, voids or caves form. This formation is called karst. As a result of karst formations, subsidence, sinkholes or funnels filled with water appear on the soil surface. The nature of these formations depends on the thickness of the layer and the composition of the soils covering the rocks.
Karst areas are considered inconvenient for urban development and are used for landscaping and recreation areas. To prevent penetration surface waters Drainage is arranged for rocks that are unstable to water and good drainage of surface runoff is organized.
When carrying out work on the vertical leveling of a karst area, large cuttings of soil should not be allowed, since this will facilitate the penetration of surface water into the thickness of the covering layer of karst. It is necessary to avoid installing structures on them, during the operation of which there will be a possibility of water leakage into the ground (water supply, sewerage, water tanks, ponds, etc.). The road route should be directed around the identified border of the karst territory in order to avoid possible subsidence and failures of the road.
Sat down
Mudflows are called mountain streams saturated a large number clastic materials and loose rocks (mud flows). Mudflows occur in almost all mountainous regions of the country. A mudflow is formed in the upper region of a mountain river as a result of rainfall on steep sections of the slope, forming water flows with high speed.
Depending on the amount and composition of the carried material, mudflows are divided into water-stone, mud and mud-stone. Such flows have the greatest destructive power.
The complex of protective measures consists of agro-land reclamation work, which is carried out to reduce the size of the resulting mudflow, as well as the construction of special protective engineering structures to combat the already formed flow. Of great importance is the preservation of grass cover, shrubs and trees growing within the mudflow-prone drainage basin.
To reduce the speed of flows, artificial obstacles are created by creating transverse furrows on mountain slopes and terracing the slopes. They build protective structures - dams, dams, dams, storage tanks.
Seismic phenomena
As a result of the action internal forces On the Earth, movements of the earth's crust occur, which are accompanied by elastic vibrations, causing seismic phenomena - earthquakes. They are constantly observed in mountainous areas. In flat conditions, earthquakes are either not observed at all, or are very rare and their strength is 1-3 points. Areas affected frequent earthquakes, are called seismic.
Earthquakes are tectonic in origin, i.e. associated with mountain-building activity (90%), volcanic and landslides that occur during the collapse of voids that appeared during the formation of karst. The source of an earthquake is called the hypocenter. The point on the earth's surface located above the center of the earthquake source is called the epicenter. Spread speed seismic waves V rocks varies depending on the age of the rocks. At the same time, the destruction of buildings is less significant than on loose rocks. In loose rocks, loosely interconnected rock masses, earthquakes propagate weaker, but at the same time are the most destructive.
In Soviet and foreign urban planning, a wide variety of schemes for constructing a street and road network are used. However, an analysis of the layout of various cities allows us to speak about the existence of fundamental geometric schemes that determine the configuration and outline of their main majority. Each of these schemes has its positive and negative sides.
The most common of them would be the following:
Fast growth car traffic in cities discovered a discrepancy between planning and technical specifications outdated city street network modern requirements transport.
Thus, practice has shown that in old cities private entrances and exits from microdistricts to main streets form a dense network of intersections, which significantly reduces the intensity, speed and safety of traffic.
In this regard, when planning new cities, it is recommended to apply the principle of sequential adjoining of one category of streets to another (the “tree” or “river” principle). Its essence lies in the fact that each transport junction must be formed either by equal categories of streets, or by streets that differ by only one category in the sequence: entrance -> driveway -> residential street -> main street of district significance -> main street of city significance –> city road (Fig. 4.3.).
In any case, the compositional scheme of the road network should not be based on formal considerations. It must be determined by the specific conditions of the area, meeting the requirements of the architectural and planning idea of building a city.
In general, when assessing the design of urban highways, one can be guided by such a general indicator as the density of the street network, which is determined by the ratio total length streets (km) to the city area (km 2).
Lecture 3 (4 hours)
1. Schemes for constructing urban road networks
2. Requirements for UDS, characteristics of UDS
3. #G0Classification of city streets and roads
4. Main technical parameters of roads and intersections
Literature:
1. Klinkovshtein, G. I. Organization of road traffic [Text]: textbook. for universities / G.I. Glinkovshtein, M.B. Afanasiev. – Moscow: Transport, 2001 – 247 p.
2. Lanzberg, Yu.S. Guidelines for the design of urban streets and roads [ Electronic resource]. / Yu.S. Lanzberg, Yu.A. Stavnichy. – Moscow: Stroyizdat, 1980. – Access mode: http://nashaucheba.ru/v34383/lanzberg_y.s.,_stavnichiy_yu.a._ed._guide_on_design_city_streets_and_roads. - Cap. from the screen.
3. SP 42.13330.2011. Urban planning. Planning and development of urban and rural settlements. Updated edition of SNiP 2.07.01-89* [Electronic resource]. – Access mode: http://docs.cntd.ru/document/1200084712. - Cap. from the screen.
Schemes for constructing urban road networks.
Planning structure cities is determined by the nature of the road network (RDN), which serves as the arteries of the city. Streets and roads are transport communications and paths for the movement of people. Water supply, sewerage, energy supply, etc. networks are fixed along them. Thus, the road network forms part of the urban area, limited by red lines and intended for the movement of vehicles and pedestrians, the laying of various networks of engineering equipment, and the placement of green spaces.
Geometric schemes for constructing road networks have a significant impact on the main indicators of road traffic, the possibilities of organizing passenger communications and the complexity of traffic management tasks.
The following geometric shapes are known: UDS schemes: radial, radial-ring, rectangular, rectangular-diagonal and mixed (Fig. 1).
Figure 1 – Street network planning systems a-radial; b – radial-ring; c – fan;
g – rectangular; d – rectangular-diagonal; e – diagonal; g – free;
h – diagram of A.H. Zilbertal
Radial the system arose naturally from the road junction. It is convenient for connecting the outskirts with the center, but does not create direct connections between the outskirts. That's why radial system highways can only be preserved in small towns. As a city grows, there is a need to create ring or diagonal connections between its districts, bypassing the center.
Radial-ring The system historically developed from a junction of roads and rings of fortress walls. Being very convenient for connecting the outskirts with the center, it at the same time has the following disadvantages in the conditions of modern large city: concentrates powerful traffic flows in the center, passing transit through it, limits the transport work of radial highways with the throughput of the center; complicates communications between residential areas along chord directions. Therefore, when reconstructing large cities with a radial-ring planning system, there is usually a need to make a number of significant adjustments to these systems - to redevelop the center by dispersing its nodes, creating new highways, rebuilding its mechanical transport networks and, in addition, creating chord highways for communication between districts of the city, bypassing the center (Fig. 2).
Figure 2 - Canberra city center (Australia) has a system of radial and ring streets.
"Fan" The planning system is like half of a radial-ring system. From the cities that arose at river crossings - on a higher, flood-free bank, roads fanned out. As the city grew, semi-circular streets were formed - often along the fortress walls. The fan system is also found in coastal port cities, located on the shores of a deep bay, and in seaside resorts, where the streets converge to the location of the park, beach and health resorts (Fig. 3).
Figure 3 – “Fan” system, plan of Kostroma
Rectangular diagram characterized by the presence of parallel highways and the absence of a clearly defined center. The distribution of traffic flows becomes more uniform. This pattern is found in a number of “younger” cities in our country, for example, in St. Petersburg, Novosibirsk, Rostov-on-Don, Volgograd, as well as in most cities in the USA. Its disadvantage is the difficulty of transport connections between peripheral points. To correct this shortcoming, diagonal highways are provided that connect the most remote points, and the circuit acquires a rectangular-diagonal structure (Fig. 4).
Figure 4 – Rectangular diagrams: map of Rostov-on-Don, master plan Manhattan
Mixed(or combined) scheme is a combination of these four types and is essentially the most common. However, it does not have its own clear characteristics. The mixed scheme, as the name implies, is devoid of clear geometric characteristics and represents functionally related, but isolated from each other, residential areas connected highways. This scheme is typical, for example, for resort areas.
Diagonal(or triangular) highway grading system is rare. Despite its undeniable advantages (low non-linearity coefficient and freeing the city center from excessive transit), it has a major drawback: complex highway nodes that reduce the capacity of the entire network.
Free the planning system with its curvilinear or broken street routes is characteristic of the plans of many cities of the Middle Ages. The high coefficient of non-straightness makes it inconvenient for major cities. Therefore, when reconstructing them, it is often necessary to break through new direct highways. However, for small cities and, in particular, with difficult terrain, a rationally thought-out open-plan system may be the most acceptable form building a street network. New open-plan systems with skillful use of terrain features have become widespread in the construction of small cities and towns in England and the USA.
