I think these penalties are in general usefull for routing optimization. On an normal 90° crossing they will be 30 sec on a 50 km/h street, which seems quite reasonable for me for car routing. This helps the routing algorithm to prefer straight lines without a lot of street changes. I'm astonished by the values. 357 sec are 6 minutes! I have tried to interpret your values and observations: Seems to me, that the penalty gets calculated by a formula similar to ((180°/x)-1)*3.3*roadSpeed. So these values are extreme values because of the extreme situation. An 15° corner on an highway is really not usual... (and I think it would need 6 minutes to sort out the traffic :-) Regards, Johann Marco Certelli schrieb:
Made some test.
during fastest route serching, garmin gives a time penalty to turns. time penalty seems propotional to road speed so I think it just calculates a speed reduction due to turn and then a linear increase of speed up to the road speed.
for a steep 15° turn I got 357 second penalty on a motorway (road_speed=6 i.e 108km/h) and 237 second penalty on a primary (road_speed=4 i.e. 72km/h)
as the angle widens, the penalty is reduced (at 45° is about 1/3 the above values, at 90° about 1/8)
Ciao, Marco.
--- Gio 28/5/09, Felix Hartmann <extremecarver@googlemail.com> ha scritto: