Bicycle assignment is an assignment that takes into account the typical behavior of cyclists. In contrast to individual motorized traffic, the route choice for bicycle traffic does not usually depend on the volume capacity ratio. In addition, cyclists have individual preferences that are reflected in their choice of different routes. In addition to travel time and distance, criteria such as safety, comfort, or the attractiveness of a route play a greater role. Factors such as the surface condition of the ground, the traffic volume or speed of motorized traffic in mixed traffic, and the type of cycling facility influence the perceived impedance, i.e. they reduce or increase the travel time on a link, for example. Other factors, such as maximum slope, may be included in the impedance as a property of the total path.
Bicycle assignment is, at its core, a stochastic assignment in which only one iteration is calculated due to the lack of vol/cap ratio dependence (Stochastic assignment). Additional searches with varying impedances generate alternative routes that are loaded after preselection and optional detour test. This means that suboptimal routes are also used.
For route choice, various choice models such as Logit, Kirchhoff, or Box-Cox are available. To take the spatial similarities of the routes into account during the distribution, a similarity measure is determined from overlapping routes – called the Commonality Factor (⇒ “C-Logit“) – or the independence of each route (according to Ben Akiva) is determined.
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Note: In the directory C:\Users\Public\Documents\PTV Vision\PTV Visum 2022/Examples, you can find examples of use on this topic. The example PrT Modeling Bicycle illustrates how bicycle traffic can be modeled in Visum and shows a suitable methodology for assigning bicycle demand to the network. For more information on bicycle traffic modeling, watch the following video: How To Model Bikes in Visum |
