Spanish River Blvd Bridge
Boca Raton FL
Photo taken by Douglas Butler in August 2014
View this photo on Flickr
BH Photo #292553
The main reason for usage of drawbridges in these locations is that for high bridges, longer approaches are required, which there is no room for in these tight areas.
When next you rebuild it for God's sake build it way higher to reduce the need for openings!!!!!!