Traffic engineering is a branch of
civil engineeringCivil engineering is a professional engineering discipline that deals with the design, construction and maintenance of the physical and naturally built environment, including works such as bridges, roads, canals, dams and buildings...
that uses engineering techniques to achieve the safe and efficient movement of people and goods. It focuses mainly on research and construction of the immobile infrastructure necessary for this movement, such as roads, railway tracks,
bridgeA bridge is a structure built to span a valley, road, body of water, or other physical obstacle, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge and the nature of the terrain where the bridge is constructed.-History:The first...
s, traffic signs and traffic lights.
Increasingly however, instead of building additional infrastructure, dynamic elements are also introduced into road traffic management (they have long been used in rail transport).
Traffic engineering is a branch of
civil engineeringCivil engineering is a professional engineering discipline that deals with the design, construction and maintenance of the physical and naturally built environment, including works such as bridges, roads, canals, dams and buildings...
that uses engineering techniques to achieve the safe and efficient movement of people and goods. It focuses mainly on research and construction of the immobile infrastructure necessary for this movement, such as roads, railway tracks,
bridgeA bridge is a structure built to span a valley, road, body of water, or other physical obstacle, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge and the nature of the terrain where the bridge is constructed.-History:The first...
s, traffic signs and traffic lights.
Increasingly however, instead of building additional infrastructure, dynamic elements are also introduced into road traffic management (they have long been used in rail transport). These use sensors to measure traffic flows and automatic, interconnected guidance systems (for example traffic signs which open a lane in different directions depending on the time of day) to manage traffic, especially in peak hours.
The relationship between lane flow (
Q, vehicles per hour), maximum speed (
V, kilometers per hour) and density (
K, vehicles per kilometer) is
Q =
KV. Observation on
limited access facilitiesA freeway is a type of road designed for safer high-speed operation of motor vehicles through the elimination of at-grade intersections. This is accomplished by preventing access to and from adjacent properties and eliminating all cross traffic through the use of grade separations and...
suggests that up to a maximum flow, speed does not decline while density increases, but above a critical threshold, increased density reduces speed, and beyond a further threshold, increased density reduces flow as well.
Therefore, managing traffic density by limiting the rate that vehicles enter the highway during peak periods can keep both speeds and lane flows at bottlenecks high.
Ramp meterA ramp meter, ramp signal or metering light is a device, usually a basic traffic light or a two-section signal light together with a signal controller, that regulates the flow of traffic entering freeways according to current traffic conditions.Ramp meters are claimed to reduce congestion on...
s, signals on entrance ramps that control the rate at which vehicles are allowed to enter the mainline facility, provide this function (at the expense of increased delay for those waiting at the ramps).
Highway safety engineering is a branch of traffic engineering that deals with reducing the frequency and severity of crashes. It uses physics and vehicle dynamics, as well as road user psychology and human factors engineering, to reduce the influence of factors that contribute to crashes.
Traffic engineering is closely associated with other disciplines:
- Transport engineering
Transport engineering is the science of safe and efficient movement of people and goods . It is a sub-discipline of civil engineering....
- Highway engineering
Highway engineering is the process of design and construction of efficient and safe highways and roads. It became prominent in the 20th century and has its roots in the discipline of civil engineering. Standards of highway engineering are continuously being improved...
- Transportation planning
Transportation planning is the field involved with the siting of transportation facilities ....
- Urban planning
Urban, city, and town planning is the integration of the disciplines of land use planning and transport planning to explore a very wide range of aspects of the built and social environments of urbanized municipalities and communities...
- Human factors engineering
Human factors is a term that covers:* The science of understanding the properties of human capability .* The application of this understanding to the design, development and deployment of systems and services .* The art of ensuring successful application of Human Factors Engineering to a programme...
See also
- Bus lane
A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport otherwise held up by traffic congestion. Often taxis and high occupancy vehicles or motorcycles and even bicycles may use bus lane as well, though these uses can be controversial since they...
/ Bus priorityBus priority or transit signal priority is a name for various techniques to speed up bus public transport services at signalized intersections. Buses normally signal their impending arrival and on their arrival at the intersection receive green lights...
/ Bus rapid transitBus rapid transit is a term applied to a variety of public transportation systems that use buses to provide a service that is of a higher speed than an ordinary bus line. Often this is achieved by making improvements to existing infrastructure, vehicles and scheduling...
- Gridlock
Gridlock is a term describing an inability to move on a transport network. The term originates from a situation possible in a grid network where intersections are blocked, preventing vehicles from either moving forwards through the intersection or backing up to an upstream intersection.The term...
- Hierarchy of roads
The hierarchy of roads categorizes roads according to their functions and capacities. While sources differ on the exact nomenclature, the basic hierarchy comprises freeways, arterials, collectors, and local roads....
- ITS
The term intelligent transportation system refers to efforts to add information and communications technology to transport infrastructure and vehicles in an effort to manage factors that typically are at odds with each other, such as vehicles, loads, and routes to improve safety and reduce vehicle...
- Microsimulation
-Econometric Microsimulation:Microsimulation is a research area in applied econometrics. It tries to simulate the behaviour of individuals over time. Microsimulation can either be dynamic or static...
- Queueing theory
Queueing theory is the mathematical study of waiting lines . The theory enables mathematical analysis of several related processes, including arriving at the queue, waiting in the queue , and being served by the server at the front of the queue...
- Road traffic control / Road traffic safety
- Route assignment
Route assignment, route choice, or traffic assignment concerns the selection of routes between origins and destinations in transportation networks. It is the fourth step in the conventional transportation forecasting model, following trip generation, trip distribution, and mode choice...
- Signal timing
Signal timing is the technique which traffic engineers use to determine who has the right-of-way at an intersection. Signal timing involves deciding how much green time the traffic lights shall provide at an intersection approach, how long the pedestrian WALK signal should be, and many numerous...
- Traffic congestion
Traffic congestion is a condition on networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased queueing. The most common example is the physical use of roads by vehicles. When traffic demand is great enough that the interaction between vehicles...
/ Traffic flowTraffic flow, in mathematics and engineering, is the study of interactions between vehicles, drivers, and infrastructure , with the aim of understanding and developing an optimal road network with efficient movement of traffic and minimal traffic congestion problems.Attempts to produce a...
/ Traffic signals