Just got back from Fla. two weekends ago. I noticed the same 6-lane 'streets' you did. I also noticed a considerable number of people riding on the sidewalks. (This was Fort Lauderdale.) Nobody seems to mind because there are no people on the sidewalks. All the people are in cars.

I was told a major hazard to bicycles is cars going 5 mph, occupied by nervous little old retirees who don't see too well. All the more reason to stay on the sidewalks.

Also ,I know the following is way off your route, but you might find it worth a side trip...

I once spent some time on Captiva and Sanibel Islands. There's one main road running through both of them, with minimal traffic.

There's also a very cool bike path running through the -- get this name -- Ding Darling Wildlife Preserve in Sannibel -- a 20-mile-ish (if I recall correctly bike and hiking trail through the swamp. You'll want to use balloon tires if you try it out. The road is partly paved but also partly hard packed sand. You'll be riding the sandy parts atop an embankment, and below there's a river/ditch/canal/whatever populated by alligators as big as your bicycle.

Personally, I'd rather take my chances with the alligators than with those 5 mph Cadillacs.

Did I mention no hills?

Have fun.

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