Surveys of highway alignment are typically completed in four stages.

1. Preliminary Survey:
The preliminary survey is the initial stage of highway alignment surveys. It involves collecting and analyzing data about the existing conditions and factors that may affect the highway alignment. This includes gathering information about the topography, geology, hydrology, and existing infrastructure in the area. The preliminary survey helps in determining the feasibility of the proposed alignment and identifying any potential issues or constraints.

2. Reconnaissance Survey:
The reconnaissance survey is the second stage of highway alignment surveys. It involves conducting a detailed field survey of the proposed alignment corridor. This survey helps in identifying and evaluating various alignment options and determining the most suitable route for the highway. The survey team collects data on the ground, such as the location and dimensions of existing roads, buildings, and natural features. They also consider factors like traffic patterns, environmental impacts, and cost implications during this stage.

3. Detailed Survey:
The detailed survey is the third stage of highway alignment surveys. It involves conducting a more precise and accurate survey of the selected alignment corridor. This survey includes the establishment of control points, setting up survey stations, and conducting field measurements to determine the exact alignment of the highway. The survey team uses advanced surveying equipment and techniques, such as total stations and GPS, to gather data. The collected data is then used to prepare detailed plans, cross-sections, and profiles of the proposed highway alignment.

4. Final Location Survey:
The final location survey is the last stage of highway alignment surveys. It involves finalizing the alignment and preparing the necessary documents for the construction phase. This survey includes the establishment of precise horizontal and vertical control points, setting out the alignment on the ground, and conducting additional surveys to refine the design. The survey team also prepares detailed drawings, specifications, and cost estimates based on the final alignment. These documents serve as the basis for the construction of the highway.

In summary, the surveys of highway alignment are completed in four stages: preliminary survey, reconnaissance survey, detailed survey, and final location survey. Each stage plays a crucial role in determining the best alignment for the highway and providing the necessary information for the construction phase.