If you open the Voyager documentation there are quite a few examples and explanations for SELECTLINK. One example for the Highway program is found at the bottom of page 291 in the latest Release Guide for Cube Voyager:
PATHLOAD PATH=COST, VOL=MI.1.ODTRIPS
PATHLOAD PATH=COST, MW=MW, SELECTLINK=(L=2001-2004),
This first PATHLOAD statement causes the COST paths to be built, and then the values from MI.1.ODTRIPS are assigned and added to VOL.
The second PATHLOAD statement causes the following sequence of events:
- COST paths are built.
- MW is set equal to the values in MW for the Js whose path from I crosses link 2001-2004.
- The values from MW are assigned to the COST paths and added into VOL volumes.
- The values from MW (the selected link trips) are assigned to the COST paths and added into VOL.
- The values from MW are assigned to only the links that are within 7.5 minutes from I and added into VOL (these are the cold start volumes).
Don’t forget though you can include several links e.g.
SELECTLINK=(L=2001-2004 && L=2004-2008) - i.e. it needs to use both links to be saved
SELECTLINK=(L=2001-2004 || L=2004-2008) - i.e. it needs to use either link to be saved
This is different for Public Transport skims which can be seen on page 735.