Why not just do traditional bike lanes (Class II)?

There are many factors considered when determining what kind of bicycle facility will be implemented during the design process. Factors such as roadway conditions, parking, speed, and driveway access. The following is a list of items the City took into consideration when determining the bicycle facility type.

Parking Maneuvers Parking maneuvers introduce a potential conflict point between bikes and vehicles, when pulling in and out of a parking space.
Speed The speed limit on North Fremont Street is currently 35 mph, higher than a typical lower volume residential roadway. Selecting a option like a Class IV separated bikeway provides a physical barrier, in the case of the project railing and a grade separation, between vehicles and bikes. This provides a safer and more comfortable experience.
Driveway Conflicts North Fremont Street has several driveways throughout the corridor, roughly one every 250 feet. At every driveway there are two potential conflict points between bikes and vehicles, one when the vehicle enters and exits the driveway.
"Dooring" "Dooring" refers to a potential collision between a parked car and a bicyclists when a motorist opens the car door to exit their vehicle. This is especially of concern as it can result in the bicyclist falling into a travel lane.
Right Turn Conflicts This potential conflict point occurs at intersections, when a vehicle crosses into the bike lane to make the right turn movement.
Left Turn Conflicts Left turns can have several more conflict points than a right turn, as bikes must move to the left crossing vehicle traffic to make a left turn. On North Fremont, there would be multiple travel lanes a bike must traverse to make a left turn.

When looking at the corridor as a whole there is a potential conflict point between bikes and vehicles about every 20-30 feet, by placing the bike facility in the median the majority these conflicts were eliminated.