Returning aggregate metrics

[araiari]

Current implementation

The current implementation of the method allows to return traffic metrics of different kinds.

1. Road-level metrics, describing the features per unit of time and per road (eg, the mean velocity and the cumulative number of the vehicles in a road in a time period);
2. Trip-level metrics, describing quantities related to full vehicular trips (eg, the travel time and the mean speed of vehicles starting in a time period).

New zone-level metrics

I am interested in "zone-level" metrics, which describe the aggregated features of roads grouped inside a "zone".

The zone-level metrics of interest are the following. Let Z be a zone (a set of roads), and t a time period:

• Distinct vehicles in zone: number of distinct vehicles traveling on any road r ∈ Z at time t
• Trip origins in zone: number of distinct vehicles starting a trip on any road r ∈ Z at time t
• Zone entries: number of distinct vehicles that are on some road r ∈ Z at time t and were on some road r' ∉ Z at time t-1
• Peak road occupancy: maximum, over all roads r ∈ Z, of the number of vehicles on r at time t
• Mean zone speed: weighted average of the mean speed on each road r ∈ Z at time t (possibly weighted)

The zonal aggregation occurs differently depending on the metric type:

• (weightedly) averaging the road-level feature (eg, when considering the mean speed)
• maximizing (or minimizing) the road-level feature (eg, the max congestion in a zone)
• starting from the raw data (eg, when computing the number of distinct vehicles in a zone)

I wonder if it would be possible to obtain either more granular information on the trips to compute the metrics above (e.g., the composition of each trip as a list of road segments and timestamps), or to obtain directly the aggregated metrics given the zonal grouping. Note that the granular trip data would only be used to re-aggregate at the zone level — I am not interested in individual travel patterns. Either approach would work for my use case — I'm open to whichever solution is easier to implement on your end.