SinkIslandCheck Ferry and Car Access Update

Description:

This update is to resolve two issues with the SinkIslandCheck.

This fixes https://github.com/osmlab/atlas-checks/issues/585. It does this by making car ferries a valid terminus for a road network. Thus ways like the following are no longer flagged: Screen Shot 2022-05-25 at 10 03 48 AM

This also fixes an issue with the way car navigability was derived from the vehicle, motor_vehicle, and motorcar tags. These tags act in a hierarchical fashion. This was previously ignored, so that if any of these tags had a navigable value the other's values were irrelevant. Example, this way was flagged because it had vehicle=yes and its motor_vehicle=permit was ignored while the connected ways just had motor_vehicle=permit: Screen Shot 2022-05-25 at 10 10 52 AM

Potential Impact:

None

Unit Test Approach:

Added unit tests for car ferries, pedestrian ferries, and car access hierarchy.

Test Results:

Analysis was done on the difference in flags from the previous version of this check to the updates here.

Subtracted Flags:	ISO	Total Flags	Sampled	Sampling %	TN	FN	Differential False Negative Rate
Global	94	94	100%	88	6	6.3%

There were 2 types of new false negative flags introduced. The first is when ferries connect piers with missing access tags: https://www.openstreetmap.org/way/822360979 The second is when ferries connected roads that had misplaced one way connections: https://www.openstreetmap.org/way/604212684

Added Flags:	ISO	Total Flags	Sampled	Sampling %	TP	FP	Differential False Positive Rate
Global	287	29	10.1%	29	0	0%

The new true positives added where situations where ways were connected to roads that had something like vehicle=yes & motorcar=no. Previously these connected ways were seen as car route-able, when in fact they should not have been. https://www.openstreetmap.org/way/784709925 https://www.openstreetmap.org/way/717145350

osmlab / atlas-checks