VISSIM 5.30-05 User Manual

Acceleration and Deceleration Functions
To reflect the stochastic distribution of acceleration and deceleration values,
each graph consists of three different curves showing the minimum, mean
and maximum values. Each curve can be edited individually.
The vertical axis depicts the acceleration value and the horizontal axis
depicts the corresponding speed. The visible range of both axes can be set
using the corresponding fields. Pressing the button BEST FIT will use the
current graph to determine the minimum and maximum values to be shown
on both axes.
Within one graph each curve can be edited separately by dragging one of its
intermediate points. When dragging points of the median curve (red dots)
both the values of the border lines are adjusted as well.
The default maximum acceleration/deceleration curves in VISSIM
The default maximum acceleration curves for cars are almost the original
ones provided with the Wiedemann 74 model, cf. section 5.4.1.
► For cars, these measurements performed in Germany before 1974 have
slightly been adapted for shorter time steps with jerk limitation and for the
user-defineable spread (min-max).
Jerk is the rate of change of acceleration; that is, the derivative of
acceleration with respect to time. With more than 2 time steps per
second, it is limited by the share that corresponds with twice the time
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