Underlying assumptions for speed and turn costs

Dear ORS-team,

Many thanks for providing ORS! For documentation of our results derived from ORS, we would much appreciate if you could provide us with the following information.

You have a detailed documentation on the driving time calculations in ORS regarding assumed driving speeds (Travel Speeds | openrouteservice documentation). However, we did not find a description of the assumptions made on time necessary for transitions from one street to another (“turn costs”; e.g. time needed for a left turn from one street into a crossing street).

Could you please describe how these transitions from one edge of the network to another are modelled in ORS and, potentially, also specify which specific assumptions are made for these transitions?

Kind regards!