https://www.cbc.ca/news/canada/calgary/future-vision-green-line-9.7230961
A bus bridge or bus link can be used whenever an LRT line is truncated, or yet to be completed. However, BRT is also used before the potential of putting in an LRT line.
Then there is an actual bus-bridge. When an existing bridge is too narrow for proper bus lanes, especially BRT, then a bus-bridge can be a big improvement.
