Let us say I have a route 'AB' and it is served by two buses tr_1 and tr_2 and the buses depart every 20 minutes and the route travel time is 15 minutes. So, buses depart at 7:00, 7:20, 7:40 etc. Once tr_1 reaches the end of the route (i.e. reaches stop B) at 7:15, can it be reassigned to the route 'AB' at 7:40 without having to simulate its travel to Stop A, via the network?
In general, once the transit vehicles reach their destinations, will they be available for transit routing for any route or is it limited only to those routes originating from its last known simulated stop location?
You can assign a transit vehicle to multiple departures. MATSim will search for a route on the network from the end of the first usage to the start of the second usage for this vehicle. So the vehicle will return empty from the end of the route back to the start of the route. It will generate traffic on the links in that case, but not accept passengers. If the vehicle gets stuck in a traffic jam, it might arrive too late for the new departure, and therefore the service on that route will be delayed.
Do I have to indicate the return route for the bus (from stop B to A) or will Matsim automatically take care of this?
On a general note, am I right in saying that this approach of using the same vehicle at regular intervals seems to lead to erroneous results, especially in cases where buses are traveling in a uni-directional route instead of a bi-directional or cyclic route? I am basing this on your statement that buses are traveling empty and at the same time adding to the traffic on roads.
Given this does it make sense to use a new bus for every departure, especially for the uni-directional routes?
MATSim will calculate the return route automatically.
What happens in the real-world? Do the buses just vanish at stop B? Do they serve the reverse route, back to A? Do they travel back empty to stop A to start another route? Depending on how the real-world is, and how the model is, the results can be erroneous, especially if the model depicts something else than the reality is (e.g only a uni-directional line is modelled, but in reality it is bi-directional).
If the line is actually bi-directional, and you only model it uni-directional, then it's best to use new vehicles for each departure, so the buses don't drive back empty.
Thanks Dr. Rieser. I think my question was slightly misstated in the sense that some of the transit routes in my scenario appear to be uni-directional (as coded by the transit agency). But, I am sure that these buses are not uni-directional and are used somewhere else. However, the transit vehicle route-assignment details are not available to me. Given this, I am forced to assume that these routes are uni-directional.
Your explanation of the details makes sense.