I spoke with Bill Hughes at Taughannock Park this morning. The Jacksonville Road parking lot is closed for a week. After that time (and since it’s a contractor, it may be fungible), half of the parking lot will be available again and the other half will be used for construction staging.
During this week, all access from that parking lot to BDT is closed, so reroute along Jacksonville Road and then Gorge Road to get to BDT. When the lot re-opens, the access to BDT will not be along the current path, but instead along the footpath at the top of the bridge that crosses the gorge. I made a video to show what that looks like. It should be fairly clear with fencing when they have it completed, too.
In the meantime, you can still scan at the sign (it’s accessible) but you’ll need to park at the two spots at BDT and Gorge, or at the Kraft Road parking lot (start/finish there) and enter times manually.