Road design and construction are critical factors for the development of any country, and Bangladesh is no exception.
As a densely populated country with a growing economy, Bangladesh needs a well-maintained and extensive road network to facilitate transportation, promote economic growth, and improve the quality of life for its citizens.
This article provides an overview of road design and construction in Bangladesh, covering topics such as design standards, construction practices, maintenance, and the impact of road infrastructure on the country.
Road Design & Construction: Overview in Bangladesh
Road design principles in Bangladesh are influenced by a range of factors, including the country’s geography, climate, and socio-economic conditions. The Bangladesh Road Research Laboratory (BRRL) is responsible for developing road design standards, specifications, and guidelines for the country’s road network.
The design of roads in Bangladesh follows the “flexible pavement” concept, which involves constructing a pavement structure with layers of materials that can distribute traffic loads over a wide area. This concept is suitable for Bangladesh’s climate, where temperatures and moisture levels can fluctuate significantly throughout the year.
Road construction in Bangladesh typically involves the following phases: planning, design, land acquisition, and construction. The construction process involves several steps, including earthwork, sub-base construction, base course construction, and pavement construction.
Materials Used for Road Construction in Bangladesh
The materials used for road construction in Bangladesh depend on the soil conditions and traffic volume. The typical materials include crushed stone, gravel, sand, and asphalt. Additionally, the use of recycled materials, such as reclaimed asphalt pavement (RAP), is gaining popularity in Bangladesh.
Construction Techniques Employed in Bangladesh
The construction techniques used in Bangladesh involve both manual and mechanical processes. Manual labor is still prevalent in many road construction projects due to the availability of a large workforce. However, the use of mechanized equipment such as bulldozers, excavators, and asphalt pavers is increasing.
Maintenance Practices in Bangladesh
The maintenance of roads in Bangladesh involves several activities, including pothole repairs, patching, surface treatments, drainage maintenance, and vegetation management. The Bangladesh Road Transport Authority (BRTA) is responsible for overseeing road maintenance activities in the country.
Factors Influencing Road Design & Construction in Bangladesh
Several factors influence road design in Bangladesh. Among the crucial elements are:
- Climate: Bangladesh’s climate is characterized by heavy rainfall, high temperatures, and high humidity levels, which can cause pavement deterioration and surface erosion. The road design should account for these conditions to ensure durability and longevity.
- Soil conditions: Bangladesh has various soil types, including soft clay, silt, and sand, which can pose significant challenges to road design and construction. Soil stabilization techniques, such as the use of lime, cement, and fly ash, are used to improve soil strength and stability.
- Traffic volume: Road design in Bangladesh considers the volume and type of traffic using the road. The design should account for factors such as vehicle speed, vehicle type, and road capacity to ensure safety and efficiency.
Various Challenges Bangladesh is Facing for Road Design & Construction
Bangladesh has been facing various challenges, which can vary in terms of design, construction, and maintenance. We will know these challenges as well as the measures taken to address them.
So, let’s go…
Challenges Faced in Road Design
Several difficulties with Bangladeshi road design exist, such as:
- Limited resources: Bangladesh is a developing country with limited resources, which can affect the quality and sustainability of road design and construction.
- Land acquisition: Acquiring land for road construction in Bangladesh can be challenging, especially in densely populated areas. Land acquisition issues can delay project timelines and increase costs.
- Lack of data: The availability of reliable data on traffic patterns, soil conditions, and other factors can affect road design and construction quality in Bangladesh.
Measures Taken to Address These Challenges
The government of Bangladesh has implemented a number of measures to address these issues, including:
- Investing in road infrastructure: The government has allocated significant funds towards road infrastructure development to improve the quality and sustainability of road design and construction.
- Improving land acquisition processes: The government has streamlined the land acquisition process to reduce delays and improve efficiency in road construction.
- Collecting data: The government is investing in collecting data on traffic patterns, soil conditions, and other factors to inform road design and construction decisions.
Challenges Faced in Road Construction
Bangladesh’s road construction faces a number of difficulties, such as:
- Quality control: Ensuring quality control during road construction can be challenging, especially in remote areas with limited access to resources and skilled labor.
- Traffic management: Traffic management during road construction can be difficult, as it can cause significant disruption to the local community and affect the safety of workers and road users.
- Maintenance: Maintenance is an ongoing challenge in Bangladesh, as the road network is extensive, and maintenance requirements can vary significantly across different regions.
Measures Taken to Address These Challenges
To address these challenges, the government of Bangladesh has taken several measures, including:
- Capacity building: The government is investing in capacity building programs to train local workers and engineers on road construction techniques and quality control.
- Technology adoption: The government is adopting new technologies such as Global Positioning Systems (GPS) and Geographic Information Systems (GIS) to improve the accuracy of road construction and maintenance.
- Road safety campaigns: The government is launching road safety campaigns to educate road users on safe driving practices and reduce the number of road accidents during construction.
Challenges Faced in Road Maintenance
Road maintenance in Bangladesh faces several challenges, including:
- Funding: Adequate funding is necessary for regular maintenance activities, but the government often faces budget constraints.
- Capacity building: The lack of trained personnel and equipment for maintenance activities is a significant challenge in Bangladesh.
- Weather conditions: The weather conditions in Bangladesh, such as heavy rainfall and flooding, can cause significant damage to road infrastructure, making maintenance challenging.
Measures Taken to Address These Challenges
To address these challenges, the government of Bangladesh has taken several measures, including:
- Increasing funding: The government is increasing funding for road maintenance activities to ensure regular maintenance.
- Capacity building: The government is investing in capacity-building programs to train local workers and engineers on road maintenance techniques.
- Adoption of technology: The government is adopting new technologies such as remote sensing and GIS to improve the accuracy and efficiency of road maintenance.
- Collaboration: The government collaborates with private sector organizations and international development partners to improve road maintenance activities.
The Future of road maintenance in Bangladesh
The adoption of new techniques and technologies, such as pavement management systems and condition-based maintenance, is likely to have an impact on how roads are maintained in Bangladesh in the future. The government’s emphasis on sustainability is also probably going to encourage the adoption of environmentally friendly maintenance methods, like using recycled materials.
All things considered, maintaining Bangladesh’s road infrastructure is essential for its long-term viability and safety. The success of the road network over the long term depends on the government’s continued investment in activities related to road maintenance and the adoption of new technologies and practices.
The Principles of Design Standards
Current design guidelines link the road’s width (geometric design) and the thickness of its different layers (pavement) to the road’s categorization. Because they are in charge of distinct classifications of roads, LGED and RHD, have differing design criteria. Most nations base their design requirements on the volume of traffic on their highways. This is due to the following effects of traffic volume:
- The width of the road must be provided for safe and effective traffic flow.
- The pavement’s expected lifespan.
Future design requirements for all roads and highways in Bangladesh should be based on traffic demand, according to the recommendation. Design guidelines are meant to take into account the safety and mobility requirements of all users of the road, not just motorized vehicles. All governments in Bangladesh as well as initiatives receiving international assistance should adhere to the suggested criteria.
Geometric Designs
Geometric design standards were adopted in 1984. In 1996, some changes to the classification of roads were made based on World Bank recommendations. Existing geometric standards are set out in the following table.
Road Class | Carriageway (m) / (ft) | Hard shoulder (m) / (ft) | Verge (m) / (ft) | Crest Width (m) / (ft) |
Rural Road 1 | 3.0 / 10 | 0.0 / 0 | 0.9 / 3 | 4.8 / 16 |
Feeder Road B | 3.7 / 10 | 0.0 / 0 | 1.8 / 6 | 7.3 / 24 |
Feeder Road A | 3.7 / 12 | 0.0 / 0 | 1.83 / 6 | 7.3 / 24 |
Regional | 5.5 / 18 | 0.0 / 0 | 2.74 / 9 | 10.98 / 36 |
Pavement Designs
The estimated number of Equivalent Standard Axles (ESAs) that will utilize the road over its lifespan informs the design of the pavement. 8.2 tons is an ESA. The average axle loads for various vehicle types are determined using data from motorized vehicles in Bangladesh. Total ESAs for the design period are calculated using this, coupled with a review of the road’s traffic mix.
This estimate already accounts for the suggestion to raise the axle weight restriction in Bangladesh. Pavement thicknesses are graphically depicted in the following figure, demonstrating a reasonable development whereby pavement thickness increases with traffic volume.
Road Reconstruction Costs
Agencies must conduct accurate surveys of the state of the roads today and account for them in project papers. The table below includes a range of actual contractual expenses as well as typical rebuilding costs for current design standards. Cost estimates for suggested designs are displayed next to them, assuming a 50% material recycling rate.
Recommended Design Type | Cost/km Lac Taka |
8 | 22.0 – 26.2 |
7 | 26.7 – 31.8 |
6 | 29.3 – 37.9 |
5 | 44.0 – 56.6 |
4* | 56.0 – 63.8 |
4 | 58.6 – 75.3 |
3 | 78.3 – 100.7 |
In general, the recommended design types’ estimated cost ranges are comparable to those of the already-existing designs. It will often be possible to save money by connecting design and traffic directly.
Benefits of Good Road Design and Construction in Bangladesh
Good road design and construction can have several positive impacts on Bangladesh. A few of these benefits include:
- Improved transportation: Good road design and construction can improve transportation networks and reduce travel time. This can enhance economic growth by facilitating the movement of goods and people.
- Increased access to services: Good road design and construction can increase access to essential services such as healthcare, education, and markets.
- Job creation: Road design and construction can create employment opportunities for local communities and contribute to economic growth.
- Improved safety: Good road design and construction can improve road safety and reduce the number of accidents.
Drawbacks of Poor Road Design and Construction in Bangladesh
Poor road design and construction can have several negative impacts on Bangladesh. Some of these challenges include:
- Traffic congestion: Poor road design and construction can lead to traffic congestion, which can impact economic growth and increase pollution.
- Reduced accessibility: Poor road design and construction can reduce access to essential services such as healthcare and education.
- Road accidents: Poor road design and construction can increase the risk of accidents, leading to injury and loss of life.
- Increased environmental impact: Poor road design and construction can have a negative impact on the environment, leading to increased pollution and the loss of natural habitats.
Case Studies on the Impact of Road Design and Construction in Bangladesh
Several case studies demonstrate the impact of road design and construction in Bangladesh. Several of these studies consist of:
- The construction of the Dhaka-Chittagong highway: The construction of this highway improved connectivity between two major cities, reducing travel time and improving access to services.
- The rehabilitation of the Amtali-Patuakhali road: The rehabilitation of this road improved access to markets and services in rural areas, contributing to economic growth and poverty reduction.
- The construction of the Padma Bridge: The construction of this bridge will improve connectivity between rural and urban areas, reducing travel time and improving access to services.
Conclusion
Road design and construction in Bangladesh play a crucial role in the development of the country’s infrastructure, economy, and quality of life. The country has made significant progress in recent years with the construction of new roads, bridges, and highways.
However, there are still challenges to be addressed, such as funding constraints and capacity building, to ensure that road infrastructure is maintained and developed in a sustainable manner.