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Next: Additional Options for Auto Assignment Up: EMME/2 News 4 October 1987 Previous: Alphanumeric Node Labels

Assignment Done - Which Modifications Are Still Safe?

In earlier releases of EMME/2, any modification of the input data in an already assigned scenario would lead to the loss of the "assigned" status of the scenario, i.e. the results of the assignment(s) were no longer available for analysis. While this is necessary when the modifications are structural (i.e. concern the information on which the assignment results are based upon), it is questionable when the data modified has no influence on the assignment results, such as e.g. the link types or the node coordinates.

In release 3.0, this aspect has undergone a complete overhaul, so that any existing assignment results are invalidated only if absolutely necessary. The following table summarizes how existing assignment results are affected by the different modifications. Note that this table describes the behavior of release 3.0 and is not applicable to earlier releases.

ModuleModificationAssignment
AutoTransit
1.23Titles, units - any modificationnono
1.41Demarcations - any modificationnono
2.01Add, modify or delete a modenono
2.02Add, modify or delete a vehicle typenono
2.11Input base networkyesyes
2.12Add or delete centroid/node/linkyesyes
Modify nodes (any attribute)nono
Modify links (length)yesyes
Modify links (transit modes)noyes
Modify links (auto mode, lanes, vdf)yesno
Modify links (type, ul)nono
2.21Input transit linesnoyes
2.22Initialize transit linesnoyes
Add or delete a linenoyes
Modify headway, speednoyes
Modify name, veh., descr., user datanono
Modify a line segment (dwt)noyes
Modify a line segment (ttf, layover)nono
Modify an itinerarynoyes
2.31Initialize turn penalty tableyesno
Add, modify or delete a turnyesno
2.41Modify nodes (any attribute)nono
Modify links (length)yesyes
" " (lanes, vdf)yesno
" " (type, ul)nono
2.43Marking of elementsnono
3.01-3.22Any modificationnono
4.11-4.14Any modification nono
5.11Auto assignment (more iterations)nono
Auto assignment (new assignment)yesno
Transit assignment (more demand)nono
Transit assignment (new assignment)noyes


next up previous
Next: Additional Options for Auto Assignment Up: EMME/2 News 4 October 1987 Previous: Alphanumeric Node Labels


Heinz Spiess, EMME/2 Support Center, Thu Jun 6 14:13:02 MET DST 1996