Hi all
For my master’s thesis I’m using the ORS Tools plugin to calculate isochrones. It is important to include the speed assumptions that are used to calculate travel time. I understand that travel time is calculated for each segment by using speed-limits for different waytypes and adjusting them for different grades or surfaces of the road. I also understand the table containing the speeds used for different waytypes on https://github.com/GIScience/openrouteservice-docs/blob/master/README.md. However I’m struggling to understand the tables on the adjustments for different grades and surfaces. For some modes these tables give a value of -1 for some grades and surfaces, and for others a positive value. What do these numbers actually mean?
Thanks in advance!