See discussion here Speed camera warns even if it is placed in the other direction · Issue #6316 · organicmaps/organicmaps · GitHub
Is a direction tag enough for data consumers to know if they should warn or not?
It seems the Organic Maps team would like another tag like front_only=yes or similar.
I think the safest method would be to add an enforcement relation. Put the “to” node at the point in the highway were the speed is actually measured (there usually is a small cabinet on the side of the street at that point), and the “from” node at an arbitrary point in the same highway a little further back. All speed cameras in my country are mapped this way.
Been mapping speed cameras in ‘speed limit enforcement’ relation with estimated to-from points on the road, some are one direction, some of these are both ways so there’s 2 ‘to’ in the relation. An example is this one with an ID Editor view
Note that in some countries it’s illegal to warn, in other countries it’s law that pre-warning signs are put up but have never mapped those (did not find it in the traffic_sign catalogue for Italy). Here the mobile units disguesed for instance as a small trailer or a second (old) civil car parked few hundred meters before the spot the cops are waiting for you to write the ticket ad hoc are effectively speed traps. Can’t map those of course.
