Harry's GPS Suite Forum

Hi Harry,

I want to ask about one thing. Sometimes I´m using speedo because it can measure avg speed. It´s usefull on roads in radar controled sections (point to point measuring). But I found a little "bug". App can´t measure avg speed with only OBD speed (in tunels). It needs GPS for it.

It´s a normal behavior?

Avg speed is derived from distance driven and time required, not some integration of actual speed values. Something like this could be done, although it requires some numeric tweaking due to the influence of data and calculation inaccuracies. Not trivial.

Harry

PS As long as the tunnel is straight, you should see proper values after leaving the tunnel again.

Ah, thanks for explanation. The tunel, where I needed most, is complicated, there are changes in elevation, corners etc. We have there 5-6 measured sections and sometimes speed limit is changed from 70 to 50 or 50 to 70 during passing (it depends on how heavy actual traffic is at the moment)

But. Distance could be calculated from speed and time, and these 2 values we have.