PTV Group - Logistics Forum

Hello,

We have a use case that we think would be solved using the ExactTimeConsiderationAtStart route option, but we would like to check with you if we understood it's purpose correctly.
What we would like to do is to check actively if a driver has gone off route by recalculating his route by also taking his current position into account, but without changing the route that he already travelled. So this is our flow with:

1. At the drive start we calculate the route A ---> B using the current time as reference
2. Every five minutes, we calculate the A ----> CarPosition ----> B route with the start time as reference (same one used at 1.) and compare time/distance to see if anything changed (either the driver took a detour, the best route changed on the distance that hasn't been covered yet because of traffic/incidents, or both).

So my question is: does the ExactTimeConsiderationAtStart guarantee that nothing will change on the route that would have been covered in the past or should we expect some possible changes and find another way to implement this?

Thank you,
John

Hi John,

ExactTimeConsiderationAtStart evaluates all data which has time restrictions at the exact time at which the route segment is reached by the vehicle.
When you perform step 2 and a traffic jam occured in the section A --> CarPosition, after you have calculated step 1, then the route from section A to CarPosition might be changed and you can have a difference in distance or time.
According to your procedure you would detect this change.

Does that answer your question or can you specify it more accurate?

Best regards,
Lars

Hello Lars,

So, if I understand correctly, the route can change only on the parts of the route that wouldn't have been covered, right? So, if I have a 2h route with a reference time 4h ago, nothing will change on that route no matter how many times I call the calculateRoute. Also, if I have a 2h route with a reference time 1h ago, only the second half of the route will be able to suffer changes. This route calculation will be called every few minutes (with the reference set at the beginning of driving) so that we can catch traffic jams and such in time, but we wouldn't like for the route to change on the part of the route that would have already been covered (the parts between reference time and time of the previous calculation). This calculation will be compared to the last calculation, not the first one, but the reference time will remain the start time, so that we can detect changes in the last minutes, not the whole covered route. Is that correct?

Thank you,
John