**5. Functional classification of urban roads**

The importance of functional classification is determined by which the role of each road is defined for the traffic and transport service. The degrees of urban roads vary according to the areas they serve, whether residential, commercial, residentialcommercial, etc. and also according to the total movement that will be generated from those areas served. Classification of roads in urban planning can be summarized as follows [6–8]:



**125**

**Table 2.**

*Building an Integrated Database of Road Design Elements*

road network and its widths about (12–16 m).

**6. Highway capacity and level of service**

service level according to the type of road [9, 10].

A The average speed is about 90% of the

B The average speed of traffic decreases due

C Travel speed is about 50% of the speed of

D Average speed 40% of free flow rate. The

E Speed of flow is 33% of free flow speed,

factor is 0.95

intersections

*Service level characteristics by road type [9, 10].*

F The average speed of traffic between

speed of free flow. Delay at intersections with traffic signals is minimal

to the delay in intersections and the impact of vehicles on some of them and about 70% of the speed of traffic. Load factor at 0.1 intersections and peak hour factor 0.8

free flow. Run balanced. Long rows of cars when traffic signals are possible

flow rate is unbalanced, and delays at intersections may be comprehensive

volume at capacity, and flow is not balanced. The coefficient of load at intersections (0.7–1.0). The peak hour

25 and 33% of the speed of free flow, high delay times at the branches of

prevailing traffic conditions.

**The level of service**

c.Urban roads of the third degree (local): Collecting vehicles from the residential areas and areas of activity to the highest road degree and carrying the least amount of traffic in the network and is the lowest degree in the hierarchy of the

The design characteristics of the road must be commensurate with the design speed chosen and expected for environmental and terrain conditions, and the designer should choose the appropriate design speed based on the planned road degree, terrain

The capacity of the road is the maximum number of vehicles expected to pass over a particular part of a lane or road during a given period of time under the

Service level is the qualitative measurement of the effect of a number of factors such as operating speed, travel time, traffic failures and freedom of maneuver, and crossing, driving safety, comfort, road suitability, and operating costs for the service provided by the road to its users. **Table 2** shows the characteristics of the

> The average speed of the road is 93 km/h or greater. Most of the crossings are carried out without delay. In the ideal case, the traffic volume is 420 vehicles/h for both directions

> The average speed of the road is 88 km/h or more. The load coefficient may be up to 0.27. Traffic volume is 750 vehicles/h for both

The average speed of the road is 84 km/h or more. The flow rate in the ideal case is about 43% of the capacitance, with a mean traffic in ideal conditions 1200 vehicles/h in both directions

The average speed is 80 km/h. The flow rate is about 64% of the capacity, with continuity in the imposition of overflow and flow of approximately 1800 vehicles/h for both

The average flow rate is about 72 km/h. The flow rate in ideal conditions is 2800 vehicles/h; level E may not be accessible as the operation is converted from service level D to F directly

The operating speed is less than 72 km/h, and the traffic are overcrowded and constrained with unexpected characteristics, volume less than 2000 vehicles/h in both directions

directions

directions

**Urban arterial Two lanes road**

characteristics, traffic volume, and economic considerations. Note **Table 1**.

*DOI: http://dx.doi.org/10.5772/intechopen.88678*

#### **Table 1.**

*Design speed of urban roads [6, 7].*

*Geographic Information Systems in Geospatial Intelligence*

tion ranging from 80 to 120 km/h.

capacity of 500–700 vehicles/h [5].

**5. Functional classification of urban roads**

**capacity and rank**

from 60 to 80 km/h.

40–60 km/h.

rized as follows [6–8]:

(16–25 m).

*Design speed of urban roads [6, 7].*

**4. Classification of road network according to the criteria of** 

• Free streets: These streets are designed for the purpose of speeding and long distances in international and regional trips, with a capacity of between 1800 and 2000 vehicles/h, with lanes ranging from 4 to 8 lanes, at a speed of opera-

• Express streets: The streets are meant to serve the largest number of citizens, high speed, long distances for regional trips, a capacity of between 1400 and 1800 vehicles/h, and lanes of 4–8 lanes, with a speed of operation ranging

• Arterial streets: The streets with medium-distance urban trips, easy access between parts of the city and a capacity of 800–1200 km/h, with a speed of

• Collected streets: These streets mean short urban trips, easy access between the city, and a capacity of 600–900 vehicles/h, with a speed of 30–50 km/h.

• Local streets: For short transport service, at a low speed of 20–30 km/h, with a

The importance of functional classification is determined by which the role of each road is defined for the traffic and transport service. The degrees of urban roads vary according to the areas they serve, whether residential, commercial, residentialcommercial, etc. and also according to the total movement that will be generated from those areas served. Classification of roads in urban planning can be summa-

a.Major urban roads: These roads link the main centers of activity in urban areas. They are connected to the regional network and take the largest traffic load in

b.Secondary urban roads: These roads collect the vehicles from the main roads and distribute them to the degree of lower roads, and their widths are about

**Degrees Minimum speed (km/h) The desired speed (km/h)**

Local road 30 50 Collector road 50 60 General arterial road 80 100 Less disturbance 70 90 Tangible disturbance 50 60 Highway 90 120

the urban area. These roads have width about 40 m or more.

**124**

**Table 1.**

c.Urban roads of the third degree (local): Collecting vehicles from the residential areas and areas of activity to the highest road degree and carrying the least amount of traffic in the network and is the lowest degree in the hierarchy of the road network and its widths about (12–16 m).

The design characteristics of the road must be commensurate with the design speed chosen and expected for environmental and terrain conditions, and the designer should choose the appropriate design speed based on the planned road degree, terrain characteristics, traffic volume, and economic considerations. Note **Table 1**.
