Thank you. There was some prior discussion about using NBI in [1], but it focused on weight restrictions rather than start dates. Perhaps you could help with the idea to map weight restrictions based on this dataset, since it seems to have stalled.

NBI could also be useful for improving road coverage in OpenHistoricalMap. OHM has mappers doing more bespoke research on road openings, but bridge-based inferences could complement that work very nicely. I proposed something similar to your process in the OHM forum. [2] Feel free to chime in based on your experience doing this in OSM. (You can log into OHM using your OSM account, then log into the forum using your OSM account.)

[1] https://community.openstreetmap.org/t/adding-bridge-information-in-kentucky-and-other-states/113229
[2] https://forum.openhistoricalmap.org/t/national-bridge-inventory/578