VISSIM 5.30-05 User Manual

Distributions
be smaller than the right number). Intermediate points are displayed as red
dots. They can be created with a single right button mouse click and moved
by dragging with the left mouse button. Merging two intermediate points
deletes the first one of them.
The horizontal axis depicts the desired speed while the vertical axis depicts
the cumulative percentage from 0.0 and 1.0. Two intermediate points are
generally adequate to define an s-shaped distribution which is concentrated
around the median value.
5.2.2 Weight Distribution
The weight of vehicles categorized as HGV can be defined as a weight
distribution. Along with a power distribution it affects the driving behavior on
slopes.
Each vehicle type is assigned to one vehicle category. For each vehicle of a
type that is defined as HGV category, VISSIM randomly selects one value
out of the weight distribution and another one out of the power distribution
that is assigned to its vehicle type. The weight and power values do not
automatically correspond to each other (i.e. it is possible that a vehicle gets a
high power and low weight assigned). VISSIM therefore computes the
power-to-weight-ratio of the vehicle as kW/t. In order to prevent extreme
power/weight combinations the power-to-weight-ratio has a range of 7-30
kW/t. If the ratio is computed lower than 7 kW/t, the ratio is internally set to 7
kW/t; if the ratio is computed higher than 30 kW/t, it is set to 30 kW/t.
According to the power-to-weight-ratio, one curve out of each
acceleration/deceleration function is selected for this vehicle proportionally.
Example: If the power-to-weight-ratio is computed as 7 kW/t, the resulting
max. acceleration curve is the lower border of the range of curves (cf. section
5.1). If it is 30 kW/t, the resulting curve is the upper border.
A Weight Distribution can be defined/edited by BASE DATA - DISTRIBUTIONS –
WEIGHT... in the same way as a speed distribution (cf. 5.2.1 for details).
5.2.3 Power Distribution
The power of vehicles categorized as HGV can be defined as a power
distribution. Along with a weight distribution it affects the driving behavior on
slopes.
A Power Distribution can be defined/edited by BASE DATA - DISTRIBUTIONS –
POWER... in the same way as a speed distribution (cf. 5.2.1 for details).
Please refer to the weight distribution for details on how the power
distribution comes into action.
User Manual © PTV AG 2011 111