Traffic forecast
A traffic forecast is a forecast that is used for the object-based forecast of traffic flows (e.g. for a section of road or a bus route) or for the forecast of the entirety of traffic demand. When planning roads, object-based traffic forecasts are used in order to be able to estimate the future traffic load and its development. Based on these forecasts, the road can be dimensioned accordingly. If the traffic development is not taken into account, there is a risk that the new road will quickly reach its performance limits, the traffic quality will decrease and the structural condition will deteriorate faster than planned. The consequences are high repair costs, construction sites and traffic jams. There are two different forecasting methods in traffic planning:
species
Model forecast
It makes sense to use the model forecast when building a new road. However, it can also be used if changes in the traffic structure or the road network are expected. Such changes include, for example, adding lanes , expanding local public transport or making significant changes to traffic management.
Trend forecast
The trend forecast can only be used for existing roads where it is clear that neither new construction nor changes in the traffic structure are to be expected. The forecast is extrapolated from the on-site traffic survey and is based on the assumption that traffic development follows nationwide traffic statistics.
The result of both forecasts is the forecast traffic volume in the unit motor vehicle / 24h.
Overall development forecasts
In addition to the methods presented for forecasting the traffic flow on individual network sections, there are a number of methods for forecasting the total traffic volume . Basically, a distinction is made between two different systems: the ex-post forecast and the ex-ante forecast.
An ex-post forecast is based on updating data on transport demand from the past. The attempt is made to use existing measurements and counts of traffic volume to work out as precise a prediction as possible about the future development of traffic demand. Ex-post forecasts are based on quantitative data series.
An ex-ante forecast examines the components that will influence future transport demand. A forecast is made individually for each sub-factor. The development of car traffic, for example, depends on the price of petrol. This would therefore act as a component of the ex-ante forecast. Such forecasts can also be carried out qualitatively using expert surveys ( Delphi method ).
criticism
The prognoses can lead to very different results, as the discussion about the BAB 14 showed.
In December 2009, the Federal Audit Office criticized the fact that the Federal Ministry of Transport, Building and Urban Development had been using outdated traffic forecasts for years and thus overestimated the expected volume of traffic. The traffic forecasts would have a "significant influence on the later construction costs". "If the road construction authorities had followed the results of their forecasts, they would have been able to save tens of millions of euros a year for the federal government from 1993 to the end of 2005".
See also
- Traffic type (traffic cell)
- Street category
Individual evidence
- ↑ Traffic forecast 2025 "A 14 Magdeburg-Wittenberge-Schwerin", IVV Aachen, 2008.
- ↑ Forecast of Germany-wide transport links in 2025, ITP / BVU, 2007.
- ↑ Expert opinion on behalf of BUND proves: There is no need for the A 14! ( Memento of July 30, 2012 in the web archive archive.today ) BUND website , accessed on April 24, 2012.
- ↑ Bundesrechnungshof (Ed.): Comments 2009 on the budget and economic management of the federal government ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Publication by the Federal Audit Office in December 2009 . (PDF file, 1.7 MB), p. 26 f.
