VISSIM 5.30-05 User Manual

12 Dynamic Assignment
Manual
adjustment
Position and size of the polygon are determined by position and size of the
segments: A horizontally-based quadratic polygon with 4 corners is
calculated. Thus the polygon fully covers all of the segments totally. The
horizontal bottom line is drawn directly underneath the undermost point of
all segments and the vertical line to the right is drawn directly to the right
from the segment point which is located outermost right. The segments
inside of the polygon do not necessarily match the initial segments.
From node conversion, overlapping
nodes might result. In this case, a
warning will appear.
► For manual adjustment of a
polygon definition cf. Edit polygon
in section ●.
► For manual adjustment of a
segment definition cf. Edit
segments in section ●
Example Converting a node multiple
times will cause the following:
► The size of the node
polygon will increase.
► Further segments are
added to the segment
definition or the size of the
segments is stretched,
respectively.
12.3.3 Edges
From the information given by the user’s definition of nodes, VISSIM builds
an abstract network graph as soon as the Dynamic Assignment is started.
The graph consists of what we will call “edges” to distinguish them from the
“links” the basic VISSIM network is built from.
There are two types of edges:
► Edges inside nodes (intra-node edges)
► Edges between nodes
The semantics of the graph that is built from the nodes is slightly different to
conventional travel model network graphs (e.g. in software products like
VISUM or EMME2):
608 VISSIM 5.30-05 © PTV AG 2011