Traffic flow
Under traffic flow refers to the flow or flux, that is, the number of traffic elements (eg vehicles ), which crosses a certain traffic area or line ( as a limiting case of surface ) per unit time.
The change in the flow of traffic with certain boundary conditions - traffic or vehicle density, average speed of any or all vehicles, the velocity distribution, clearance, road width - is a complex area of research, as many phenomena are not linear writable. Traffic simulations - whether from the German speaking here as an example VISSIM - are so far an important tool to support the analytical models. In particular, the conditions for the transition of unobstructed flow to stop-and -go traffic, and congestion are interesting. Applications are research results in the so-called telematics.
Traffic flow analysis
Traffic flow analysis can take place at different scales:
Influence on the flow of traffic
Land transport
Land transport can be divided into road and rail transport, and inland waterways.
Road
In road transport, the term refers to the use of transport paths through the moving traffic. This means that the traffic flow increases due to higher speed only once, but may be about the disproportionally increasing distances or through greater speed differences and associated mutual disabilities also decrease again.
Factors for the optimization of traffic flow are:
- Behavior of the individual driver, eg by accelerating at traffic start and cooperative driving.
- Influence of the traffic flow through Verkehrsleitanlagen what part on motorways in Germany through control of speed limits or shared lanes via an electronically controlled display panels. In cities, in turn, there is the challenge of traffic control in the correct establishment of the cycle times of the traffic lights.
- Systematic phenomena - such as when at a certain density of traffic congestion arises out of nowhere, as described in the Nagel-Schreckenberg model.
- Transport planning, which has set up the transport infrastructure according to the needs and entertain as well as aspects of the environment are taken into account.
Measures for the optimization of traffic flow are:
- Speed signal and Green Wave
- Reduction of the conflicting directions of traffic in a transportation hub.
- Multitrack expansion
Rail transport
In rail transport, the term refers to the use of transport paths through the moving traffic. This means that the traffic flow increases due to higher speed only once, but may be about the disproportionally increasing distances or through greater speed differences and associated mutual disabilities also decrease again.
Factors for the optimization of traffic flow are:
- Modern train control and Hochgeschwindigkeitszugeinheiten associated with better track alignment on high-speed lines, with the omission of terminal stations.
- Extension of the time window in the transport hubs in the metropolitan areas.
- Skillful time management, in off-peak hours to perform renovation and repair work and suspend track work during peak periods.
- Inserting additional carriages and special trains on special occasions.
Shipping
In shipping, the term refers to the use of transport paths through the moving traffic. This means that the traffic flow increases due to higher speed only once, but may be about the disproportionally increasing distances or through greater speed differences and associated mutual disabilities also decrease again.
Factors for the optimization of traffic flow are:
- Block clearance on movable bridges and locks ( within the city)
- Expansion of natüriichen waterways in order to achieve constant depth ( within the city)
- GPS and Nautical to secure a higher vehicle throughput ( within the city)
- Broadening of the harbor entrances and improve fairway ( maritime )
Traffic
In aviation, there is the concept of traffic flow even though an aircraft used during the flight assigned air corridors and other altitudes. This only while landing ground traffic, and start rolling process and that precise time window must be respected.