They are only as accurate as the crowd can determine either by on-site visits or by finding permit information in City/County documentation. Sometimes we don't find them until they show up on someone's in-car nav. I'd say the norm is to find them at some point in their construction phase. Supercharge.info cannot be taken as authoritative as only Tesla has the complete set of information but it is the best out there besides Tesla. Here are a couple living visualizations to see the bigger trends in supercharger construction:Are they typically accurate with build out times or do those numbers indicate something else / come from some standardized building permit?
- scatter plot with time in permit stage on one axis and time in construction on the other.
- Bar chart showing time in permit stage from longest to shortest
- Bar chart showing time in the construction phase from longest to shortest.
- Supercharger trends