Looking at it I have a hard time believing they would have ramps capable of supporting bike traffic. I would guess stairs on both sides with an elevator to accommodate disabilities. Besides are you really going to ride up a ramp that steep just to cover 100 feet of road and go down the other side? It would be easier to just go down to the stop lights.
The west end of the bridge extends all of the way across University Ave to the stadium. The gameday foot traffic from the eastern parking lots would be separated from vehicular traffic on University Ave and also from the parking/tailgating area east of the stadium and then terminate at the concourse level in the stadium . The Alamo Bowl has a similar concept as do many other stadiums, event centers, downtowns, airports, Vegas, Scheman/Hilton, etc. It's more of a skywalk than just a pedestrian bridge.
There are many of them in the Des Moines area; Grand View University over NE 14th St, downtown skywalk system, MercyOne Hospital downtown, the Des Moines Airport, etc.