How is the arrival time determined?

The Stop Detection algorithm determines when a vehicle arrives at a stop according to the Control Tower. Stop detection is a rather complicated algorithm, because it has to be able to deal with complicated situations. For example, multiple stops at neighboring houses close together, or a route that passes very close to a later stop. 


Wherever possible, the Control Tower uses manually drawn 'Geofences' to precisely delineate stop locations. In their absence, a circle is drawn automatically around the address. A setting determines the size of the circle. The default value is a radius of 100m.


In principle the arrival time is: the first moment that the vehicle is stationary within the geofence (a so-called 'standstill_event'). In case that cannot be determined, there are fallback options such as the first detected point within the geofence or de Area fence.


Example of a manually drawn Geofence:



Example of two automatically generated Geofences close together:



These 'fences' can be made visible in the Control Tower by activating the 'Breadcrumb' setting (and zooming in far enough on the map):


A Geofence or Area fence is a digital line around an area. We usually just call this a fence. Whether the presence of a vehicle inside a fence also leads to a registered stop depends on a number of conditions:

  • There must be several GPS points close to each other within the fence;
  • The vehicle must spend a minimum amount of time inside the fence. This time period is a setting. For example, for home deliveries it can be set to 3 minutes. For transport operations with loading and unloading it will be a bit longer;
  • Optionally, a minimum percentage of the planned stop time (or loading time) that must be spent inside the fence can be set;
  • There are 'catch' functions, such as that a very clear stop right next to a fence is also registered as a stop, under adjustable conditions;
  • It is possible to set whether or not stops are allowed to be registered in a different order (deviating from the planning);
  • There is a 'window' around the planned time of a stop within which it will be registered, these maximum 'too early' and 'too late' values can be set separately;
  • Depending on the type of vehicle and on-board computer, stopping the engine of the vehicle can also be considered as proof of stopping;
  • The speed of the vehicle is monitored: if it is 0, there is a standstill. This is also a condition to register a stop.



Analysis in case of arrival time problems


Problem: A stop has incorrectly not been registered.


Below are a number of possible explanations if this occurs:

  • The GPS registration was not correct. No points have come through at all, or the 'gps drift' was so great that the points were too far apart or even outside the fence. Occasionally, there is also a problem with a device whereby the points are seen hundreds of yards away from the actual location. The solution in these cases is usually a check of the device or the app used by the driver. It can also be a temporary connection problem if it recovers itself later.
  • The stop was shorter than the set minimum time. If this happens often, it is advisable to adjust that setting.
  • The driver was too early or too late, or deviated from the planning sequence where this is not allowed.
  • The journey was already completed according to the Control Tower, because the last stop had already been completed (rightly or wrongly). Subsequent stops are ignored in this case.
  • The previous trip of the vehicle is not yet completed, because the last stop(s) of this trip were not registered. The solution is to manually 'complete' the stops of the previous trip, the data will then be processed and the active trip will be 'recovered' (there is a time limit for this, default is 4 hours).



Problem: A stop was registered even though it did not happen


Below are a number of possible explanations if this occurs:

  • The driver stopped for several minutes near the stop location, for example due to a break, a traffic light or traffic jam, as a result of which the stop was registered too early. Stopping there again will then no longer be registered. This is something to bear in mind when drawing geofences (e.g. so that a motorway or intersection is not accidentally included). This is also a risk if several locations are very close to each other.
  • If the same location occurs more than once in a route, this can also go wrong. For example, if the driver leaves the geofence briefly during the first stop and then enters it again (e.g. because of a break or because a detour is made between loading and unloading), this can wrongly be seen as two stops instead of one. This can be solved by drawing Geofences wider and setting the maximum 'too early' value correctly.
  • A 'neighbour delivery', because two stops are close to each other, it concludes that both have already been visited although in fact only one has. If this happens a lot in your operation, feel free discuss possible improvements with Simacan.