Symptom

A developer considers using DirectDistance as an alternative to ExistingDistanceMatrix for planTours optimization, hoping it will allow dynamic constraint application without a pre-computed matrix.

Cause

DirectDistance is sometimes confused with a lightweight routing mode. It is not a routing mode; it computes straight-line (as-the-crow-flies / Euclidean) distances between points.

Resolution

Do not use DirectDistance for logistics optimization scenarios that require real road constraints. It does not consider:

• Road network topology
• Tunnel restrictions or ADR codes
• Weight, height, or dimension restrictions
• Turn restrictions, one-way streets, or road closures
• Actual driving distances or travel times

DirectDistance is appropriate only for quick approximations where exact road routing is irrelevant, for example when pre-filtering a large set of candidate stops for a rough feasibility check.

For all production logistics planning with real vehicle constraints, use either:

• ExistingDistanceMatrix with a properly configured HPR (fixed profile, high performance)
• xRoute with VehicleParametersAtWaypoint (dynamic per-leg recalculation, higher latency)

Related articles

PTV xServer 2: PTV_TruckAttributes feature layer: role and requirement for ADR routing 

PTV xServer 2: Dynamic vehicle state changes not supported in ExistingDistanceMatrix planTours 

PTV xServer 2 :ADR tunnel restrictions not applied in planTours when using ExistingDistanceMatrix 

PTV xServer 2: Route divergence after changing vehicle parameters (height, weight)