Highway Engineering Design
PAVED ROAD ENGINEERING AND HIGHWAY ENGINEERING DESIGN
Highway engineering design is a complex branch of civil engineering, encompassing not only the determination of load requirements and structural pavement design, but also the elements of road geometry and traffic flow. All of these aspects must come together to arrive at the optimum design solution for specific roadway construction or highway construction projects.
The geometric design consists of horizontal alignment, vertical profile, and cross-sectional elements. Combined, they provide a three-dimensional layout for a roadway.
- The alignment is the route of the road, defined as a series of horizontal tangents and curves.
- The profile is the vertical aspect of the road, including crest and sag curves, and the straight grade lines connecting them.
- The cross section shows the road structure, water management elements such as ditches and culverts, curb configuration, number of lanes, etc.
Structural pavement design encompasses the materials, quantities and composition to achieve the desired load capacity and longevity.
The goal of contemporary highway engineering design is to create a structure that will serve virtually in perpetuity, which has given rise to an industry term—“perpetual pavement”. Perpetual Pavement describes an enduring structural design, construction and maintenance concept for asphalt pavements. A perpetual pavement is intended to be designed and constructed to last longer than 50 years without requiring major structural rehabilitation or reconstruction, and only periodic surface renewal in response to typical distresses experienced from cyclic traffic loading.
To meet this expectation, the science of highway engineering design embraces innovative technologies. The application of geosynthetics in pavement structure vastly increases the base modulus of both paved and unpaved roads. NPA geocells, a 3-D cellular confinement system, can be used for base reinforcement in highway engineering design to increase the service life of the structure.
NPA geocells and other geosynthetics also provide a sustainable solution for paved road and highway reconstruction and rehabilitation. NPA geocells’ 3D confinement improves the performance of infill materials, enabling the use of locally available soil as well as recycled materials such as on-site reclaimed asphalt as a base course. With the costs of conventional road construction materials rising, as well as the desire to reduce CO2 emissions released by roadway construction activity, the economic and environmental value of paved road and highway rehabilitation using geosynthetics becomes clear.
Stratum Logics is a civil and geotechnical engineering company that employs roadway design specialists with unique expertise in the application of NPA geosynthetics in highway engineering design and roadway construction. When geosynthetic components present the best solution from economic, sustainability and environmental standpoints, Stratum’s engineers can design paved roads and highways with a long life expectancy, making perpetual pavement a reality.