SADC trunk road shields

[1ec5]

Routes belonging to the SADC Regional Trunk Road Network in Southern Africa are tagged network=sadc and should be marked by orange-on-blue hexagons.

[ZeLonewolf]

Seems decently mapped. This is equivalent to an e-road or the Asian network, so we should render this. To be consistent with our style guideline and other shields, the orange backdrop should get removed in favor of a stroked orange line.

[1ec5]

We’re unable to render these routes correctly because of what seems to be incorrect tagging:

• Some of these relations are tagged int_ref=* instead of ref=*. int_ref is only necessary for distinguishing the common and international reference numbers of a feature, typically on a way that would be numbered concurrently by multiple authorities. But these route relations are already international by definition, and a single route relation cannot represent a concurrency by itself.
• Other relations in this network are tagged ref=*, but all of the int_ref and ref values begin with SADC, which is similar to the problem described in https://github.com/ZeLonewolf/openstreetmap-americana/issues/141#issue-1125053298.

Once the tagging issues are fixed, it’ll be trivial to support network=sadc. Here’s a shield we can use:

[1ec5]

SADC member states are in various stages of implementing the SADC-RTSM. A spot check of some highways in Zimbabwe that have been upgraded to SADC signs shows that the trunk road shields aren’t necessarily being posted. For example, there’s a new SADC sign at this intersection in Bulawayo but only an indication for the R2 highway in plain text (no shield).