It can be really hard to get valuable opinions from the public.
I've been a part of the process on both sides of the fence. From my experience, it's only hard when an entity attempts to ram a project down the public's throat. On the other hand, getting good feedback is a pretty easy and rewarding process when you work within the community's long term vision and goals.
The informed and wealthy can afford lawyers, engineers, and other professionals to force FDOTs hand in many cases.
In the Fuller Warren's case, the informed only exposed precedence and enforcement of policies already in their books. In other words, the community demanded better. In return, FDOT responded and did just that.
To flip the example back on you, what about the landowners along the FCE corridor, or any other future corridor? I refer to them as special interests, yet they actually own the land and are affected by the project.
Haha. One huge difference. The community didn't ask for the Fuller Warren Bridge expansion or an additional flyover. It was forced upon them. In the case of the FCE, that was all about special interest and major land owners looking to profit from worthless dirt increasing in value with the construction, accessibility and visibility provided by an expressway.
Also, the cost didn't get cheaper because of the shared use path. Come on, lake. It was the flyover at Roosevelt.
Being involved in the process, the shared use path wasn't an isolated thing. Modifying the flyover to eliminate its negative impacts was another major issue tackled simultaneously. The result is a product that achieves FDOT's original goals that also fits into the surrounding context.....for $16 million less than the original.