Hi Heather,
Thank you for looking into this. This is very much appreciated. Answers to your questions are below.
1. I'm trying to understand your problem a little more. It seems like you are wanting one driver to pick up someone/something at location 1, drive to location 2 and then back to location 1 with that same person or item. Is this correct?
That is correct. An example would be the driver picking up a certified cheque and location 1, needing it take it to location 2 to pay for the item they are picking up and then returning to location 1. The route cannot be done in reverse because location 2 will not release the item until the cheque has been received.
2. Is there a certain amount of time at location 2 that the person or item needs to stay there? and if so can the driver go to a different location to pick up a different order during that time or does the full round trip need to happen before the driver can do anything else?
The certain time the driver would have to be on site at location 2 is included in our request for service time (5 min). The driver cannot leave and come back before picking up the return. However, the driver could make additional stops in between – on their way from location 1 to location 2 or on their way back from location 2 to location 1. As long as trying to maintain the time constraints.
3. If the driver is allowed to do something else while waiting for picking back up from location 2 is it possible to then have two orders on the vehicle at once or would a full pickup and drop off need to be done during that time?
In this business case – the driver needs to deliver the cheque, then pick up the return in that order.
4. When expanding the problem to multiple routes, is it a hard requirement that the return trip is done by the same vehicle/driver or could that be done by a different route in the area?
Yes – the driver that does the delivery must also be the driver doing the return. If it was ok to have different drivers doing the orders, we wouldn’t need to actually link the orders in any way.
Please let me know if you have any other questions.