question

First, you can use getvarnum() instead of getnodenum(getvarnode()):

getvarnum(TRANSPORT,"totaltraveldist")

Second, you can use a Statistics Collector to collect data into a table for charting on a dashboard.

Attached is an example model (track-flowitem-travel-dist.fsm) that listens to the OnEntry of a Sink object where task executer flowitems go to leave the model.

When they leave, it records an entry for each flowitem with columns for the time it left and its total travel distance.

I've plotted that data onto a Time Plot to show Travel Distance vs Time with a dot for each flowitem at the time it left the model.

This example may not be exactly what you are trying to collect, but hopefully you can learn what you need to from it and customize it according to your needs. If you can't figure out how to make it collect exactly what you want, please post an example model showing what you are trying with a more detailed explanation of what you want it to do.