Road or highway development process involves different Stages such as road planning, road design, right of way, road construction, road operation and road maintenance. Road design is one of the important road development process. Road design involves positioning the physical elements of the road way according to guidelines and standards. The purpose of any road design is to provide a safe, efficient, economical and environmentally compatible road transport system.
Road devices such as road surface markings are necessary in order to guide, create awareness on road users on some inherent features of the road on safety concerns. Moreso, a road way cannot be complete if it doesn’t have adequate road devices that can give prior notice to motorists on certain conditions of the road.
Road Design Considerations
Road design considerations are factors to be put into consideration when practicing systematic road design. They include; safety, environmental, cost, maintenance, highway function.
Safety must be ensured when designing a road. It is the principal consideration. All road designs have maximum safety as their objective.
Road design should be made in accordance with the preservation of environmental status quo and environmental enhancement. A feasibility study of the environmental impact assessment of the road must be done. Thus, road designers should work in line with environmental bodies for recent guidelines
The economization of a road design cost without sacrificing other considerations is the designer’s goal. Cost/benefit analysis may be used, when appropriate for consideration of the cost implications of a road design.
Under constructability, limitations on the construction methods, technology, and materials should be considered. The designer should become familiar with the construction practices and use the standard specifications for road and bridges construction
Road maintenance work begins after the construction is completed. Error or insufficient design causes additional maintenance effort or may require further construction to correct the design flaws
The road functional idea is important to the road design. Consideration must be given to the expected role the road is to play based on the location and environment is to be sited.
Factors Influencing Road Design
Road design is based on a number of factors Influencing it. The three main factors Influencing road design are; traffic volumes, design elements and environmental considerations
Upon designing a road, traffic volume is taking into consideration to ensure that the quality can sustain the expected traffic.
The road design element includes
- Travel lanes and pavement
- Vertical and horizontal alignment
- Sight distance
- Drainage channels
- Super elevation
- Design speed
Environmental plays a major role in developing road projects. Through out the duration of the road project, a close working relationship is needed between the environmental and the designated staff assigned to each project to identify potential environmental impact seeks alternatives to avoid such impacts to the extent practicable and develop appropriate mitigation measures as necessary.