Highway engineering indicates a form of civil engineering that deals with the design and construction of roadways. Engineers working in this field might work as design engineers or highway traffic engineers. Each area of specialty requires specific analysis and planning using mathematics and science.
A highway engineer responsible for designing streets determines the most effective paving materials for the type of road and its expected use. The engineer considers flexible and rigid materials for the base of the road and its final layer, which usually consists of cement or asphalt. He or she uses formulas to determine the amount of stress the highway can endure, service life of the materials, and how quickly ruts or roughness might appear, for single-lane and multi-lane roads.
During the geometric design process, highway engineering involves both vertical and horizontal alignment. An engineer determines the optimal sight distance for braking and passing on curves and near underpasses. He or she considers the braking capabilities of traditional braking systems and anti-lock brakes installed on some vehicles.
Highway engineering also looks at aerodynamic features of the roadway and how they impact safety. The grade of the highway should also be sufficient to allow proper drainage without affecting acceleration and braking. Fuel efficiency and driver comfort represent other factors engineers consider when designing new roads, along with impacts to the environment.
Some highway engineering involves traffic studies to measure the capacity of a street and whether traffic flows without undue congestion and bottlenecks. The engineer might look at how a new road impacts all other highways in the area. He or she studies the number of accidents in the vicinity, how the road will be used, and how driver behavior might influence safety.
Intersection design represents one aspect of highway engineering applied to urban areas. Engineers recommend traffic control systems to obtain the best traffic flow, especially during peak hours of use. They determine whether stop signs, yield signs, or traffic signals are warranted using simulations and models common in the industry. If signals are planned, engineers determine the timing of lights, the cycle length, and coordination of signals to improve traffic flow.
Highway engineering in urban areas analyzes public transportation and mass transit systems and their effects on surface roads. Pedestrian needs are also weighed when planning traffic control devices, based on statistical information. An engineer working on traffic issues might also use models to predict future traffic needs, working with officials familiar with projected growth.