Since their emergence in the 1930s, transport planning and engineering have developed a range of concepts which help planners to design networks and road infrastructures. 30th-hourly volume, peak 15-minute period, average daily traffic etc. Parallel though not integrated in these approaches, several economically oriented evaluation concepts, such as the cost-benefit analysis, have been conceptualized. The research need is the development of a modern dimensioning concept for transport infrastructure. The concept shall suitably consider the variability of travel demand as well as the infrastructure's capacity.
Aim of the project is the development of a modern dimensioning concept for transport infrastructure. The concept shall suitably consider the variability of travel demand as well as the infrastructure's capacity.
The working method of the project consists of the iteration of theoretical development of the approaches, practical review of examples and discussion of manageability with practice and the relevant specialists and experts commission.
The new method calculates the time losses, which are caused over the course of a year by short-term breakdowns in traffic flow. The likelihood of such a breakdown for a given traffic
volume is estimated empirically drawing on a records of the Swiss automated traffic counting stations. This probability is understood as the product of the probability distributions of the
instantaneous capacity and traffic flow. The duration of the breakdown for a given volume is estimated empirically. The values of travel-time-savings and of reliability are taken from the
appropriate Swisss guidelines SN 641 820ff.
Further research and application will have to show, if the additional information provided by this more complex method is justifying the additional effort requried for practical applications.