Wow, those are some seriously long transition times. If you're working with a large site model, I'd suggest something along the lines of 10-20m/s for motion speed. Of course, it all depends on whether you want fly-by, drive-by, or walk-by speed, and the physical size of the site/campus.
As it is, you can use the multiplier. Select all scenes, use 1/5 as your multiplier, then click the "Apply to Selected TT", then click "Save Changes". That will speed things up considerably.
The Transition Time is a time in seconds that it takes to transition from one scene to the following scene. Your TT of 80 seconds for scene 1 is a LONG TIME. That's why I suggested using 1/5 for your multiplier - it will yield a 16 second TT (and other selected scenes will also be reduced by 80%).
Hope that helps...