VISSIM 5.30-05 User Manual

Automobile Traffic
will disregard any routing decisions while it still travels on a previous one. For
a vehicle to successfully move from one route to another, the start of the
second route must be placed downstream of the previous one.
An easy way to accomplish this is to place all green sections of a route on
the first connector (or similar position on a link) after the last decision point
for that route. By placing all red sections (routing decisions) always on a link
after the junction (after all connectors ended) it is ensured that all previous
routes ended prior to the start of the next one (see illustration below).
As with any decision point the routing decision affects a vehicle only the
time step after it has crossed the decision point. Therefore, the distance
between a routing decision point and the first connector should be, at a
minimum, equal to the distance a vehicle travels with the highest desired
speed within one time step.
Vehicles assigned to a specific route and waiting for a gap to merge will be
removed from the network after a waiting period of 60 seconds to avoid
unrealistic backups. The assumption is that in reality those vehicles would
have forced their way into the flow.
The default value of 60 seconds can be changed in the driving behavior
parameter set (cf. section 5.4).
If VISSIM cannot find a connection between the routing decision point (red
bar) and the destination point (green bar) usually a connector is missing.
In this case double-check the desired link sequence using the Center line
viewing mode (VIEW – CENTER LINE or default hotkey CTRL+A).
User Manual © PTV AG 2011 233