Category Archives: TRANSPORTATION ENGINEERING

Flyovers and bridges : Features and difference

Flyovers and bridges are essential transportation structures that enable the seamless movement of vehicles and pedestrians. While both serve similar purposes, flyovers navigate intersections efficiently as elevated roads, while bridges connect points over bodies of water or valleys. Their distinct features make them vital components of modern infrastructure. This article is about the features and advantages of Flyovers and bridges and the difference between flyovers and bridges.

  1. What is a flyover?
  2. What are the benefits of flyovers?
  3. Types of flyovers
  4. Classification of flyovers based on Materials
  5. What are bridges?
  6. Difference between Flyovers and Bridges
  7. Purpose
  8. Design of flyovers and bridges
  9. Location of flyovers and bridges
  10. Traffic Flow of flyovers and bridges
  11. Integration
  12. Environmental Factors
  13. Length and Span

What is a flyover?

A flyover, also referred to as an overpass or an elevated roadway, is a transportation infrastructure that provides a dedicated elevated route for vehicles to traverse over obstacles such as intersections, congested areas, or other roads.”Designers create flyovers to enhance traffic flow, reduce congestion, and improve overall transportation efficiency.”

Constructors typically build flyovers above ground level, enabling vehicles to bypass busy intersections or intersections with heavy pedestrian traffic. Generally, by separating the flow of vehicles from crossroads and pedestrian crossings, flyovers minimize traffic conflicts and ensure uninterrupted movement. This in turn results in smoother traffic flow, reduced delays, and improved safety.

Flyovers and bridges

The construction of flyovers requires careful planning and engineering. Generally, builders often use reinforced concrete or steel girders to construct flyovers, providing structural support for vehicles and the ability to bear substantial loads. The design includes ramps or access points to enable smooth vehicle entry and exit onto the flyover, ensuring seamless integration with the current road network.

What are the benefits of flyovers?

The benefits of flyovers include:

  1. Improved traffic flow: Basically, Flyovers separate the flow of vehicles, reducing congestion and ensuring smoother traffic movement.
  2. Reduced travel time: By bypassing intersections or congested areas, flyovers enable faster and more efficient travel, saving time for commuters.
  3. Enhanced safety: Flyovers minimize the risk of accidents by eliminating conflict points between vehicles and pedestrians or conflicting traffic streams.
  4. Increased capacity: Flyovers can increase the capacity of road networks by providing additional lanes or routes for vehicles.
  5. Better fuel efficiency: Reduced congestion and smoother traffic flow on flyovers contribute to improved fuel efficiency and reduced emissions.
  6. Enhanced connectivity: Flyovers connect different parts of a road network, improving accessibility and connectivity between areas.
  7. Improved urban aesthetics: Well-designed flyovers with landscaping, architectural features, and decorative elements can enhance the visual appeal of urban landscapes.
  8. Economic benefits: Efficient traffic flow facilitated by flyovers can boost economic productivity by reducing transportation costs and improving logistics.
  9. Minimized environmental impact: Generally, flyovers can help reduce air pollution and noise pollution by minimizing congestion and idling time at intersections.
  10. Improved emergency response: Flyovers provide unimpeded routes for emergency vehicles, enabling quicker response times during emergencies or disasters.
Flyovers and bridges

Types of flyovers

Flyovers are classified based on the following factors

a) Classification based on the formation

b) Classification based on materials

  1. Straight Flyovers: Follow a straight-line trajectory, providing a direct route over obstacles.
  2. Curved Flyovers: Incorporate curves or bends in their design, accommodating specific road alignments or geographical constraints.
  3. T-Junction Flyovers: Connect perpendicular roads at a T-junction, allowing for uninterrupted traffic flow in multiple directions.
  4. Cloverleaf Flyovers: Form a circular or cloverleaf-shaped interchange, facilitating smooth merging and diverging movements between roads.
  5. Diamond Flyovers: Feature a diamond-shaped interchange, allowing for efficient access and exits from multiple directions.
  6. Multi-Level Flyovers: Comprise multiple layers or levels, providing complex interchanges with ramps and access points for different roads.
  7. U-Turn Flyovers: Enable U-turns or reverse movements, allowing vehicles to change direction without disrupting traffic flow.

Classification of flyovers based on Materials

  1. Prestressed Concrete Flyovers: Constructed using precast prestressed concrete segments that provide strength and durability.
  2. Steel Flyovers: Built using steel girders, offering flexibility in design and allowing for longer spans.
  3. Reinforced Concrete Flyovers: Constructed using reinforced concrete beams or slabs, offering a balance between cost, strength, and ease of construction.
  4. Composite Flyovers: Combination of steel and concrete elements, leveraging the advantages of both materials for optimal structural performance.
  5. Cable-Stayed Flyovers: Supported by cables attached to tall towers, offering an elegant and efficient structural solution for longer spans.
  6. Box Girder Flyovers: Consists of hollow box-shaped beams, providing strength, rigidity, and resistance against bending and torsion forces.
  7. Extradosed Flyovers: Hybrid of cable-stayed and prestressed concrete flyovers featuring shorter towers and fewer cables while maintaining structural integrity.

What are bridges?

Engineers design bridges to connect two points over a body of water, a valley, or any physical obstacle. They typically comprise abutments, piers, and a deck or roadway for transportation. The construction of bridges involves using diverse materials like concrete, steel, or wood, which depend on factors such as span length and the required load capacity. However, They serve as crucial transportation links, facilitating the passage of vehicles, pedestrians, and sometimes, even trains. Bridges provide essential connectivity, improve accessibility, promote trade, and enable social and economic development by overcoming natural barriers and creating efficient transportation routes.

Types of bridges

Bridges and flyovers

Difference between Flyovers and Bridges

Here are the key differences between flyovers and bridges

Purpose

BridgesFlyover
Bridges are primarily built to connect two points over a body of water, a valley, or any physical obstacle.Flyovers are constructed to navigate intersections, congested areas, or other roads efficiently, providing an elevated route for vehicles.
Purpose

Design of flyovers and bridges

BridgeFlyover
Bridges are typically designed with piers or support that span across the obstacle, supporting a deck or roadway.Flyovers are designed as elevated roadways, often supported by columns or piers, allowing vehicles to bypass intersections or congested areas.
Design

Location of flyovers and bridges

BridgeFlyover
Bridges are commonly found over bodies of water, such as rivers, lakes, or seas, or in areas with significant topographical variations like valleys or canyons.Flyovers are usually constructed in urban areas with heavy traffic, where they can provide efficient bypasses for intersections or congested road segments.
Location

Traffic Flow of flyovers and bridges

BridgeFlyover
Bridges accommodate two-way traffic, allowing vehicles to travel in both directions.Flyovers typically facilitate one-way traffic flow, with separate lanes or ramps for entering and exiting.
Traffic flow

Integration

BridgeFlyover
Bridges are integrated into the existing road network, connecting two points and providing a continuous route.Flyovers are designed to integrate with existing roads, providing seamless connectivity by allowing vehicles to enter and exit at designated access points.
Integration

Environmental Factors

BridgeFlyover
Bridges often need to consider factors like water flow, tidal forces, or seismic activity, depending on their location.Flyovers focus on addressing traffic congestion and improving transportation efficiency, with less consideration for natural elements.
Environmental factors

Length and Span

BridgeFlyover
Bridges can vary in length and span depending on the distance they need to cover, ranging from short spans to long suspension or cable-stayed bridges.Flyovers are generally shorter in length compared to bridges, spanning a specific area such as an intersection or congested road segment.
Length and span

Understanding these distinctions can help in determining the appropriate infrastructure solution based on the specific transportation needs and challenges of a given location.

Camber in roads – Types of Road Cambers

Camber in roads is the slope or angle built into the road surface, typically seen on curved or sloped sections of the road. This slope is designed to provide several benefits, including improved drainage, enhanced vehicle stability, and better driver visibility. The purpose of camber on roads is to ensure safe and comfortable driving conditions for motorists.

The slope can be positive, negative, or zero, depending on the specific requirements of the road and the expected traffic flow. The appropriate camber for a road depends on various factors, such as the type of road, its location, and the expected speed and volume of traffic. Proper design and construction of road camber can significantly improve road safety, reduce the risk of accidents, and increase the lifespan of the road surface.

  1. Types of Camber in roads
    1. Positive camber in roads
    2. Negative camber in roads
    3. Zero camber
    4. Composite camber
    5. Sloped camber/straight camber
    6. Two straight-line camber
    7. Barrel camber/Parabolic camber
  2. Significance of road camber
  3. Advantages of Camber on Roads
  4. Recommended Values of Camber in Road For Different Types of Road surface by IRC: 
  5. Disadvantages of excessive road camber

Types of Camber in roads

Camber in roads, or road camber, refers to the slope built into the road surface, typically seen on curved or sloped sections. The road’s camber is usually indicated by the ratio 1:n or as a percentage. Proper camber design and construction are crucial to improve road safety, reduce accidents, and ensure adequate drainage and vehicle stability.

Here’s a list of the types of camber used in road design and construction:

  • Positive camber
  • Negative camber
  • Zero camber
  • Composite camber
  • Sloped or straight camber
  • Two straight-line camber
  • Barrel camber

Positive camber in roads

Positive camber refers to the angle of a vehicle’s wheels where the top of the tire tilts outward from the centre of the vehicle. This can provide improved stability and handle in certain driving situations, such as high-speed cornering. However, excessive positive camber can lead to uneven tire wear and decreased handling performance.

Positive camber

Negative camber in roads

Negative refers to the angle of a vehicle’s wheels where the top of the tire tilts inward towards the centre of the vehicle. This can provide improved grip and handling during cornering, as the tire maintains more contact with the road. However, excessive negative camber can lead to uneven tire wear and reduced straight-line stability.

Negative Camber

Zero camber

Zero camber refers to the angle of a vehicle’s wheels where the tire is perpendicular to the ground and the wheel is vertical. This is considered the ideal angle for tire wear and handling, providing a balance between straight-line stability and cornering grip. Many production vehicles are designed with zero camber for optimal performance and safety.

Composite camber

Composite camber refers to a combination of positive and negative camber on a vehicle’s wheels. In order to achieve optimal handling and performance in specific driving situations, one can adjust the angle of each wheel independently to create a custom setup. This allows for a personalized approach to handling and can be achieved through the use of composite camber. Composite camber is a technique commonly utilized in high-performance vehicles and motorsports to attain maximum grip and control.

Composite Camber

Sloped camber/straight camber

Sloped camber refers to a wheel angle where the tire leans towards the inside or outside of the vehicle, creating a slope. Straight camber refers to a wheel angle where the tire is vertical and perpendicular to the ground. Sloped camber is often used in motorsports to improve cornering performance, while straight camber is more common in street vehicles for better tire wear and handling.

Straight line/ sloped

Two straight-line camber

Two straight-line camber refers to a setup where the camber angle is set to zero for both front and rear wheels. This provides a balanced setup that promotes even tire wear and stable handling. “People commonly use two straight-line camber in street vehicles, SUVs, and pickup trucks, prioritizing comfort, safety, and longevity over high-speed cornering performance.”

Two straight line Camber

Barrel camber/Parabolic camber

“In drifting and racing applications, people commonly use barrel camber to promote tire grip . This in turn improves cornering performance by adjusting the camber angle and toe settings on each wheel independently. Barrel camber is a wheel angle where the center of the tire is lower than the edges, creating a barrel-like shape.”

Barrel Camber or parabolic camber

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Significance of road camber

Road engineers provide camber to promote safe and efficient driving. They use positive camber on curves and turns to offer better stability and prevent vehicles from sliding off the road. On the other hand, they use negative camber on straight sections to enhance tire traction and lower the risk of hydroplaning in wet conditions.

Advantages of Camber on Roads

Camber provides several advantages for road safety and efficiency. “Moreover,” positive camber assists vehicles in remaining centered on the road while turning. This in turn results in decreased skidding and improved stability. Negative camber improves tire contact with the road on straight sections, increasing traction and reducing hydroplaning risk. Camber also helps to reduce tire wear by distributing the load evenly across the tire surface, promoting longer tire life. Overall, camber is a key design feature in road engineering. This helps to promote safe, efficient, and sustainable transportation for all.

Road

The Indian Road Congress (IRC) provides recommended values for camber in road design, based on the type of road surface. These values are as follows:

  1. Flexible Pavement on Earth Embankment
  • Straight: 1.5%
  • Crossfall: 2.5%
  1. Flexible Pavement on Soft Soil
  • Straight: 2%
  • Crossfall: 3.5%
  1. Rigid Pavement on Earth Embankment
  • Straight: 2%
  • Crossfall: 3%
  1. Rigid Pavement on Soft Soil
  • Straight: 2.5%
  • Crossfall: 4%
  1. Bituminous Wearing Course
  • Straight: 1.5%
  • Crossfall: 2.5%

“These values provide general guidance only and depend on local conditions, traffic volume, and other factors. It is important to note that.”

Disadvantages of excessive road camber

Providing excessive road camber height can have several disadvantages. These include:

  • Uneven tyre wear: Excessive camber height can cause the tire to wear unevenly, leading to reduced tire life and increased maintenance costs.
  • Increased fuel consumption: High camber angles can increase rolling resistance and reduce fuel efficiency, leading to higher fuel consumption and greenhouse gas emissions.
  • Reduced braking performance: Excessive camber can reduce the contact area between the tire and the road surface, reducing braking performance and increasing stopping distances.
  • Reduced stability: High camber angles can reduce vehicle stability, especially at high speeds, making the vehicle more difficult to control and increasing the risk of accidents.
  • Uncomfortable ride: Excessive camber can cause the vehicle to ride harshly, transmitting more shocks and vibrations to the occupants, leading to discomfort and fatigue during long journeys.

Bitumen for roads – Bitumen Uses, Grades and Types

Bitumen for roads is an important topic to understand when it comes to road construction. Bitumen is used in road construction because of the wide range of features and advantages it possesses over other pavement construction materials. The significance of bitumen in the construction of roads will be demonstrated in this article. In addition, we shall see bitumen road layers, various bituminous materials, cutback bitumen, bitumen grade, and bitumen properties.

  1. Bitumen for roads – Bituminous binder types
    1. Bitumen vs Tar – Comparison
    2. Tar manufacturing
  2. Desirable properties of bitumen- an important topic in bitumen for roads
  3. Bitumen for roads – Types of Bituminous materials
    1. Cutback bitumen
    2. Bituminous emulsion
  4. Grade of bitumen for roads – Types and Uses
  5. Bitumen road layers

Bitumen for roads – Bituminous binder types

There are two types of bituminous binder for road construction.

  • Bitumen (by distillation of crude oil)
  • Tar (Produced from coal)

So, what are the difference between them?

Bitumen vs Tar – Comparison

The table below shows a comparison between tar and bitumen.

BitumenTar
Petrolium productDistillation of coal or wood
Soluble in carbon disulphide and carbon tetrachlorideSoluble in toluene only
Temperature succeptibility is lowTemperature succeptibility is higher than bitumen
Free carbon content is lessFree carbon content is more
Comparison between tar and bitumen

Now, let’s sneak into the manufacturing of tar, being one of the important bituminous materials

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Tar manufacturing

Bitumen for roads - Construction in progress
Bitumen for roads – Construction in progress

Generally, tar is made by heating coal inside a chemical apparatus. Most tar is produced from coal as a byproduct of coke production, but it can also be produced from petroleum, peat or wood.

The major steps in tar manufacturing are,

  • Coal undergoes carbonation and produces crude tar
  • Crude tar undergoes distillation/ refining and produces a residue
  • The residue blends with distilled oil fraction and produces tar

I am going to tell more about the properties of bitumen now.

Also read: Classification of roads-5 types of roads full details

Desirable properties of bitumen- an important topic in bitumen for roads

Bitumen for roads - Properties
Bitumen for roads – Properties

The desirable properties of bitumen are,

  1. Viscosity of bitumen during mixing and compaction is adequate
  2. Bituminous material should not highly temperature and susceptible
  3. In presence of water the bitumen should not strip off from aggregate
  4. The adhesive property of bitumen binds together all the components without bringing about any positive or negative changes in their properties
  5. Bitumen is insoluble in water and can serve as an effective sealant
  6. Due to versatility property of Bitumen it is relatively easy to use it in many applications because of its thermoplastic property
  7. Bitumen play a vital role in distributing the traffic loads on the pavement to the layers beneath

Bitumen for roads – Types of Bituminous materials

Okay. So, what are the types of bituminous materials that are used in flexible pavement construction? Below is the list for you.

  1. Paving grade material
  2. Modified bituminous binder
  3. Cutback bitumen
  4. Bitumen emulsion

Among the list, cutback bitumen is the major. Let me tell you more details about cutback bitumen.

Cutback bitumen

Cutback bitumen is the bitumen the viscosity of which is reduced by a volatile diluent. It is used in low-temperature mixing.

Three types of cutback bitumen are available

  1. Rapid curing
  2. Medium curing
  3. Slow curing

The diluent while mixing varies with the type of cutback bitumen.

Type of cutback bitumenDiluent
Rapid curingNafthal, gasoline
Medium curingCarosine or diesel oil
Slow curingHigh boiling point gas oil
Type of cutback bitumen and suitable diluent

Bituminous emulsion

bitumen emulsion
Bitumen emulsion

A bitumen emulsion is a liquid product in which a substantial amount of bitumen suspended in a  finely divided condition in an aqueous medium and stabilized by means of one or more suitable material

Three types of bitumen emulsions are available

  1. Rapid setting
  2. Medium setting
  3. Slow setting

Also read: Alignment of road: Factors affecting- obligatory points with figures

Grade of bitumen for roads – Types and Uses

To determine the grade of bitumen, penetration test is conducted. The results are expressed in 1/10 mm. When penetration value is represented as 80/1000, it is called grading of bitumen.

The old method of grading is viscosity test. Two viscosities kinematic and absolute and penetration value by penetration test results are collected. Based on this, bitumen is graded. The tables shows the grade of bitumen and values of viscosity in accordance with penetration.

Grade of bitumenAbsolute viscosityKinematic viscosityPenetration
VG 1080025080- 100
VG 20100030060- 80
VG 30240035050- 70
VG 40320040040- 60
Grade of bitumen and viscosity

Let me tell you the application of each of the grade of bitumen now.

VG- 10- Used in spray application since viscosity is very less

VG- 20- Used in cold area

VG- 30- Commonly used in India

VG- 40- High grade bitumen used in high traffic areas

Okay. So, lets’ learn about the bituminous layers.

Bitumen road layers

Let’s first look into the road layers to understand bitumen road layers.

 bitumen road layers
bitumen road layers

The bitumen road layers come in the surface layer shown in the figure above. The figure below shows that. Bituminous mix consists of aggregate and binder. Aggregate consists of coarse aggregate, fine aggregate and filler less than 0.075mm.

Bitumen road layers
Bitumen road layers
  • Bituminous concrete consists of aggregate and bitumen.
  • Thickness of base course depends on grading of aggregate
  • Dense graded aggregates are provided in base course. That is the permeability will be very less
  • Number of voids should be very less
  • Dense bituminous macadam should be given as a binder course

So, the trip is over. Hope the time you spend for reading about the bitumen for road was worth it.

MUST READ: Road margins- 6 types of road margin in highway

Happy learning!

Intelligent transportation system – Components of Intelligent transportation system

Intelligent transportation system is a hot topic among all civil engineering subjects that has gained popularity and many countries are successfully implementing it. With the rapidly exploding population, ITS has even become a mandatory technique in all countries. Here, we are going to read through the main components of the intelligent transportation system. We will swim through the benefits of intelligent transportation system in the middle, then to uses and challenges of ITS.

  1. What is intelligent transportation system?
  2. Components of intelligent transportation system
  3. Benefits of intelligent transportation system
  4. Uses and challenges of intelligent transportation system
    1. 1. Use of cameras equipped with automatic number plate recognition(ANPR)
      1. Advantages
      2. Challenges
    2. 2. Speed violation recording cameras
      1.  Advantage
      2. Challenges
    3. 3. Cameras for recording violations of passing through red-lights at intersections
      1. Advantages
      2. Challenges
    4. 4. Equipping the transportation system with GPS
      1. Advantages
      2. Challenges
    5. 5. Use of intelligent routing systems for public transportation passengers
      1. Advantages
    6. 6.  Modern informative systems for offenders
      1. Advantages
      2. Challenges

What is intelligent transportation system?

What is Intelligent Transport System is the first step to dive in the topic. They are advanced applications which, aim to provide innovative services relating to different modes of transport and traffic management and enable various users to be better informed and make safer, more coordinated, and ‘smarter’ use of transport networks. In ITS the information and communication technologies are applied in the field of road transport, including infrastructure, vehicles and users, and in traffic management and mobility management, as well as for interfaces with other modes of transport.

Another answer to the question of what is Intelligent transportation system (ITS) is that, it is the application of sensing, analysis, control and communications technologies to ground transportation in order to improve safety, mobility and efficiency. ITS includes a wide range of applications that process and share information to ease congestion, improve traffic management, minimize environmental impact and increase the benefits of transportation to commercial users and the public in general.

Now, let me walk you through the main components of intelligent transportation system.

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Components of intelligent transportation system

Components of intelligent transportation systems

The main components of intelligent transportation system are,

1. Accurate tracking system
GPS enabled vehicles along with smartphone apps will help citizens to track buses and other vehicles.

2. Electronic timetables
Schedules of bus service should be updated in standard format which can be easily read by people and utilised by softwares.

3. Smart model to predict time of arrival
Transportation studies like that be conducted in IIT Madras, funded by Ministry of Urban Development. should be encouraged to obtain a robust algorithm to predict the arrival time of buses, which is what a citizen needs.

4. Standardisation by regulating authority

This is very important among all the components of intelligent transportation system. An authority should be set up which can standardise various components of the public transport and encourage the use of better and smart IT services in transport sector

5.Smart commuting

Latest information on traffic jams, accidents and ways for navigation

6. Mobile technology

App based technology, incentives for young technical entrepreneurs

7. Smart traffic control

Dynamic controls of traffic signals instead of current static control, automated system.

8. Scalability

The ITS should be easily applicable to 2nd tier cities so that problem of congestion doesn’t arise in the first place

9. Improved and better BRT system enacted with public participation

10. Installing CCTVs on traffic routes and in buses.

11. Creation of flyover and overbridges to eliminate need of traffic lights

12. Electronic payment of fare

13 Traveller’s advisory system like the use of advisory radio, SMS services, internet etc

14. Highway Management Systems: Use ramp metering techniques to measure and regulate by knowing the traffic entering or leaving the highway

15. Emergency Management Systems: To manage any unforeseen emergencies

16. Railroad Crossing: Gives signals about approaching rail junctions

17 Wireless communication System

18. Safe driving Support System

This includes,

a) Right turn collision prevention system

b) vehicle detection system
c) Pedestrian detection system

d) voice guidance

e) display warning

18. Electronic toll payment System

19. Computational technologie

20. Inductive loop detection and sensing technology

21.Freeway management.

Cool! Now how are these components of the intelligent transportation system benefiting transportation? Let’s see below.

Benefits of intelligent transportation system

traffic at night - Components of intelligent transportation systems

The main benefits of intelligent transportation are as follows.

  • Develop (and subsequently renew), a secure and effective revenue collection system – this has formed the backbone of the ITS
  • Develop enhanced operations management capabilities to provide reliable services and deal with disruptions
  • Provide communications for staff security
  • Provide improved passenger information
  • Obtain data for planning, resource optimisation and performance monitoring
  • To assist the achievement of the quantity and quality of the service required in the service contract with the province of Florence

• To generate the trip logs, analysis and reporting required by the province of Florence under the service contract

• To manage the daily operations, on both normal and disrupted state

• To manage the driver vehicle handovers and shift-changes

• To provide the platform for real-time and other information to passengers

• To provide the platform for e-ticketing

• To identify vehicle faults and assist rapid response

• To support demand responsive transport and other non-standard mobility services

• To generate and manage data for post-event analysis, including running time analysis, scheduling, resource optimization, and incident investigation

So, I walked you through the important benefits of intelligent transportation system.

Its time to see the results now.

Uses and challenges of intelligent transportation system

Components of intelligent transportation systems

1. Use of cameras equipped with automatic number plate recognition(ANPR)

Equip the intersections with traffic light crossing violations recording system and video surveillance cameras monitoring traffic flow

Advantages

Cameras are capable of fining any number of offending vehicles simultaneously

Challenges

  • Drivers cover the number plate of their cars daily in order to not to be fined
  • Some drivers who repeatedly pass specific passages try to destroy or damage the cameras and their equipment.

2. Speed violation recording cameras

Fixed cameras equipped with radar technology are assembled to identify and record speed violations

 Advantage

Assured of getting fined through being caught on camera, drivers rarely attempt to drive over the speed limit

Challenges

  • After identifying the locations where the cameras are installed, drivers may attempt to increase their speed in the distances between cameras, and this may cause many disturbances in traffic flow.
  • Due to the weakness of technology, identifying motorcycles is not possible in this system

3. Cameras for recording violations of passing through red-lights at intersections

Cameras are assembled at intersections  to record the red light running violations.

Advantages

A decrease in this kind of violation will have a direct effect in reducing car crashes and capital loss.

Challenges

  • In many intersections, due to the low quality of crosswalks and zebra crossings, it is really hard to determine a threshold running from which enables the driver to be known as an offender
  • As in many intersections, turning left or right is not legally forbidden, it is really a hard job to distinguish the vehicles doing so from the violators.

4. Equipping the transportation system with GPS

Position of the buses and the approximate arrival time of buses to stations can be calculated those who are speeding or using unauthorized routes can be identified

Advantages

  • Reduction of dangerous high speed of buses
  • Decreasing of delay time of journey

Challenges

  • Some drivers try to deactivate the GPS before attempting violation. They cover the GPS with aluminum foil to make it disconnected from the center.
  • Due to the need for a GPRS platform for sending the information to the center, using this system in Tehran is very expensive.
  • Due to the low average educational level of drivers and users of public transportation services, the relevant systematic training for using this system will be needed.

5. Use of intelligent routing systems for public transportation passengers

Passenger can receive information about the journey duration and the best manner of navigation after determining the origin and destination and also specifying the desired transportation mode such as metro, taxi, bus or walking

Advantages

 Decrease in delay of journeys and an increase in productivity.

6.  Modern informative systems for offenders

All fine notifications and notices for a technical test will be informed to the offenders via SMS

Advantages

  • Deliver the fine notifications to the offenders, omitting the process of printing and stuffing envelopes with fine notification
  •  Informing all offenders of their violations in an online manner, and creating a cohesive database of the offenders.

Challenges

  • As the telecommunications system and necessary infrastructure have not been completely developed, some problems in sending the SMS to offenders have been occasionally observed.
  •  Informative limitations such as length of words in SMS.

That’s it about ITS.

Continue learning!

MUST READ: Basic of civil engineering; Simple and in-depth guide

Bitumen Softening Point Test – Ring and ball method

The bitumen softening Point Test is done to determine the consistency of bitumen. Bitumen is a viscoelastic material, which means it behaves like both a liquid and a solid state. It does not have a specific melting point. As the temperature increases, the bitumen becomes softer and the viscosity of the bitumen decreases. One of the common parameters for classifying bitumen is the softening point of the bitumen. This property shows at what temperature the bitumen softens. 

Bitumen Softening Point Test

Bitumen softening point is measured in different ways such as:

  • Ring and Ball Method (R&B)
  • Krämer-Sarnow Method (KS)
  • Mettler Softening Point Method
  • Capillary Method
  • Flow Point Method
  • Drop Point Method

The ring and Ball method is the most frequently used to determine the softening point of bitumen.

Bitumen roads
Bitumen roads

Why Is The Bitumen Softening Point Important?

To pave the roads and aeroplane runways, it is necessary to use a type of bitumen that has a specific degree of softness. Choosing a suitable bitumen with a good softening point depends on the weather condition and traffic loads.

For example, if the average temperature in a region is high during a year, bitumen with a    higher softening point should be used to make asphalt pavement. If during the year, the number of vehicles crossing this road is high and they put a  lot of pressure on the road surface, more bitumen should be used in the asphalt. This work increases the strength of the asphalt.

Related posts – Bitumen

International Standard Methods of softening point test

The softening point  test  of  bitumen  is  in  the  accordance   with  the following standards:

  • ASTM D36
  • ASTM E28-67/E28-99
  • ASTM D6493 – 11
  • IS 1205
  • EN 1427
  • IP 58
  • ISO 4625
  • JIS K 6863

The most common standard method for determining the softening point of bitumen is ASTM D36, which we will discuss further. You can see the steps of the Ring and ball method through the Video produced by the Infinity Galaxy team.

Softening point test of bitumen – Ring and ball method (Video)

YouTube video
Youtube video

Softening Point Test Procedure

The ring and ball method is widely used to determine the softening point of bitumen. In  the  infographic  below, you  can  see  a  summary  of  the  bitumen softening point test:

Softening point test procedure
Softening point test procedure

The required equipment to do the bitumen softening point test are:

  • Two steel balls
  • Two brass rings
  • Beaker
  • Thermometer
  • Heater
  • Knife
  • A glass surface 
  • Bitumen
  • The bases holding the rings

Bitumen Softening Point Test Steps:

  • In the first step, it is necessary to prepare the test sample. Heat the bitumen to a   temperature between  75  and 100 °C. Stir the bitumen well until it becomes completely liquid and free of air and water bubbles. Heat the rings to the approximate temperature of the bitumen. Prepare a mixture of glycerin and dextrin in equal proportions.
  • Cover the surface of the metal or glass plate with it. Pour the heated bitumen into the rings to fill them. After cooling in the air, it is necessary to draw the extra bitumen with a heated knife at an angle of 45 degrees on the surface of the rings. So far you have understood how to prepare the sample.  In the following, we will explain the process of conducting this test.
  • Place the rings filled with bitumen on the bases and place them in a water bath with a temperature of 5 °C for 15 minutes. Cool the steel balls to a temperature of 5 °C. Put them in the beaker and fill them with distilled water up to about 50 mm above the rings. Now place the steel ball in the centre of the ring and tangent to the bitumen and heat it until the temperature rises 5±0.5 °C/min.

Ring and ball method – Results

  • As the temperature increases, the bituminous material softens and the balls sink through the rings. Continue heating until the balls on the bitumen reach the surface of the metal blade under the rings and note the temperature when each of the balls contacts the bottom of the plate. Consider the average of the two temperatures obtained as the bitumen softening point.
  • An important point in this experiment is the process of heating the beaker and its contents, i.e. bitumen.   Since this test is very sensitive to heat, it is necessary to use the same heating rate throughout the test. It should be noted that if the bitumen is blown and hard, glycerin liquid is used instead of water.

Penetration Test for Bitumen – Significance and Procedure

The penetration test for bitumen is a laboratory method for grading bitumen based on its hardness. In this test, the amount of penetrating a specific needle into the bitumen is measured.

More than 85% of bitumen is used in road construction. Weather condition affects on bitumen binder. In cold weather, bitumen becomes hard, and the possibility of cracking increases. On the other hand, hot weather causes bitumen becomes soft and sticky.

Both situations are not acceptable as a result of civil engineers using penetration tests.

What is the Penetration Test of Bitumen?

The penetration test for bitumen is a laboratory method for grading bitumen based on its hardness. In this test, the amount of penetrating a specific needle into the bitumen is measured.

This value is reported in a tenth of a millimetre or Deci-millimeter (DMM) as a penetration value. The penetration test can be used for refinery bitumen, emulsion bitumen, and oxidized bitumen. Based on this test bitumen is classified into penetration grades of 20/30, 30/40, 40/50, 50/60, 60/70, and 80/100.

This test can measure the penetration value in the range of 20 to 300 dcmm. It can recognize the bitumen consistency and stability of bitumen.

Let’s see this test history and application.

The Bitumen Penetration Test History

The first uses of the penetration test, date back to the early 19th century. Before that, the hardness of bitumen is measured based on the Chewing test. It was a completely experienced test. Through that, an engineer chews a moderate-temperature bitumen sample. Then reports the hardness of bitumen according to the difficulty of chewing. Because of the chewing test’s inaccuracy, the penetration test was introduced to the industry. 

An overview of the Bitumen Penetration test Importance

More than 85% of bitumen is used in road construction. Weather condition affects on bitumen binder. In cold weather, bitumen becomes hard, and the possibility of cracking increases. On the other hand, hot weather causes bitumen becomes soft and sticky. Both situations are not acceptable as a result of civil engineers using penetration tests.

Bitumen with high penetration values is suitable for cold weather. Because it does not harden and crack when exposed to low temperatures. On other hand, bitumen with smaller penetration values is suitable for hot weather. Because high temperatures can not soften it. Most workable penetration bitumens are penetration grades 60/70 and 80/100. Penetration grade 60/70 can apply to road construction in warm weather and 80/100 is suitable for cold weather.

Bitumen penetration grade 80/100 means that the needle penetrates into the bitumen in the range of 80 to 100 decimeters.

How Is the Penetration Test of Bitumen Performed?

In the following, you can familiarise yourself with the apparatus and the procedure of the test based on ASTM D5. Before that watch the below video by Infinity Galaxy which introduces the penetration test of bitumen.

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 Apparatus

  • Penetrometer 
  • Container
  • Water bath
  • Stopwatch
  • Thermometer
penetrometer

Procedure 

In the first step, bitumen should be heated up until it becomes liquid. Bitumen should not be heated in a temperature range above 90-100 degrees Celsius otherwise it will burn. While the temperature rises, stir the bitumen to make sure it is uniform. Bitumen should also be free of water and air bubbles.

In the next step, pour the melted bitumen into the container and let it cool at room temperature. 

After that put the bitumen container in the water bath with a constant temperature of 25 degrees Celsius and let the sample reach the same temperature.

Then place the container under the penetrometer. Move down the needle just above the bitumen surface. 

Thereafter, apply the needle which has a 100gr load just for 5 seconds. Repeat the test 3 times and write down the results each time. The needle tip in each repetition should be apart 10mm from the previous measurements.

Report the mean value as the penetration value of the bitumen sample. The following picture is other important bitumen tests in road construction:

Infographics – 10 Major bitumen tests