Roads Planning, Design, Construction and Maintenance

In this modern day world, roads network play major roles in economy of a country as everyday transportation of passengers and goods depends on it. A good network of roads will provide efficient and cheap accessibility to everyone and everywhere. The environmental factors such as noise and air pollution caused due to road networks, however, cannot be ignored. It is therefore, very important that road networks shall be properly planned.

Step 0: Planning of Roads

• Identify the available routes and new routes between locations
• Determine the population served by each route
• Determine the rough cost of each route
• Determine the traffic impact caused by each new route
• Identify the most feasible case.

Step 1: Topographic Survey

• Determine the area to be surveyed
• Create a survey plan outlining survey boundaries and specific areas of interest
• Establish control points and benchmarks for the survey
• Conduct field work to collect data, including elevations, locations of existing features (such as trees, buildings, and waterways), and geotechnical information
• Use survey equipment such as total stations, GPS units, and/or LiDAR technology to collect data
• Process the collected data and create a topographic map

Step 2: Preliminary Design

• Use the topographic map to create a preliminary road alignment
• Consider factors such as terrain, drainage, existing infrastructure, and environmental impacts when designing the road
• Conduct geotechnical investigations to determine soil conditions and identify any potential issues that may affect the design
• Consider safety features such as guardrails, barriers, and signage
• Estimate the costs associated with the preliminary design

Pre-Development and Post-Development Stormwater Analysis

Development can have a significant impact on stormwater drainage in an area. The quantity of land available for water to infiltrate into the soil is decreased when natural surfaces like bare ground or grass land are converted to impermeable surfaces like highways, buildings, and parking lots. This can lead to higher runoff during rain events. Flooding, erosion, and property and infrastructure damage may result from this.

Additionally, because development alters the hydrological regime also known as amount and speed of water flowing, it may have an impact on downstream flooding. The amount and speed of water flowing into streams and rivers thus rises along due to increased runoff. As a result, flooding may occur downstream of the built region and stream flows may increase.

Downstream flooding can also be largely caused by the decrease in floodplain storage capacity as a result of development. Natural floodplains have the capacity to temporarily store floodwaters, minimising their effects downstream. Development in flood-prone areas, however, may result in the loss of these natural floodplain storage areas, reducing their capacity to lessen the effects of downstream flooding.

Stormwater management techniques like low-impact development, green infrastructure, and various types of stormwater detention ponds can be used to mitigate these effects. Through encouraging infiltration, evapotranspiration, and the natural treatment of stormwater runoff, these measures work to control the volume and velocity of runoff. By limiting direct runoff of stormwater, these strategies can reduce the likelihood of infrastructure and property damage both locally and further downstream. It can also help in prevent flooding, and protect water quality.

Increased development without mitigation measures can cause flooding in the downstream areas as we have witnessed recently during several events in Pakistan.

ESSENTIAL STEPS TO CARRY OUT STORM WATER ANALYSIS

Before carrying out stormwater analysis, it is essential to collect baseline data on the existing conditions in the area. This data can be used to assess the potential impacts of development on stormwater runoff and design appropriate stormwater management strategies.

The following are the steps to carry out stormwater analysis before and after development:

1. Collect existing data: 

Collect existing data on the area such as topography, land use, soil type, vegetation cover, hydrology, and climate.