Support for avoiding flood-prone ways

[ftrebien]

Describe the idea

Supporting OSM's flood_prone tag could be useful by adding an "Avoid flood-prone roads" option and/or a "No flood-prone roads" option to the Avoid roads menu. This would allow users to enable these options during heavy rain events. Users may also find it useful to be able to set a period during which the option will be active.

Expected behaviour

If "No flood-prone roads" is enabled, routing should avoid these roads entirely. If "Avoid flood-prone roads" is enabled, routing should apply a significant penalty to them, choosing them only if other options are much longer or slower. If an auto-off timer is set, the option would become disabled automatically after the user set time had elapsed.

Alternatives you've considered

Manually selecting roads to avoid, but this is time consuming, may require research, and in some places the information may not be available, especially early in the weather event.

Context

Some regions around the world experience seasonal or intermittent heavy rainfall followed by localized flooding. Local OSM mappers can map roads known for a history or trend of flooding, and this data can be used to reduce the chance of users being routed through flooded roads during these weather events. This heuristic feature may provide better crisis routing than commercial alternatives, which often underperform in such scenarios. This is particularly useful in areas where an offline GPS is needed and up-to-date flood information is less likely to be available.