Travel time calculation

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 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!

1 Like

Hi @Simon.delrue,

The positive values (as stated above the table) are given in km/h for the specific waytypes/surfaces and tracktypes. A value of -1 means that there is no restriction for this profile-waytpe (etc) combination based on the type of way (surface…). Leaving the cell empty would have also been an option. But to differentiate between not applicable (-) e.g. cycleway for driving-* profile we put -1.

Best regards