The <b>OSRM Directions</b> algorithm calculates routes either
  1. for a single point layer (this produces a single route),
  2. for a multipoint layer (produces one route for each multipoint feature),
  3. between features of multiple layers.


When two input layers are provided, routes will either be computed for each pair (<i>all by all</i>), or for corresponding pairs only (<i>row by row</i>, either based on provided layer fields or by simple feature order).

The output layer is a LineString layer with the attributes <i>durations</i>, <i>distances</i>, and – optionally – IDs .
