I think a much better idea would be to promote the use of smaller vehicles (like Smart cars or Mini Coopers) that have to meet crash requirements and that cannot be mistaken for a golf cart.
30-A is a heavily traveled traffic artery and the high amount of (clueless or fancy-free) visitors makes this idea a very bad one IMO.
Yes, you can take 98 if speed is your major concern to get to Destin or PC or 331, but there are not enough alternate routes or N/S connectors to lower the speed limit and encourage even slower moving vehicles w/o causing major issues for many businesses, residents, and visitors.
Semis, oversize loads of building equipment and materials, garbage trucks, delivery trucks (furniture, UPS, Fed-Ex, food, beverage, gas, landscape), dump trucks, firetrucks, ambulances, and other large vehicles HAVE to use 30-A and they do NOT need to be sharing the road with golf carts!
And don't get me started on the horrific probability that they will frequently be driven by kids w/o licenses and be full of unrestrained little kids (which we all know will happen).
I am all for promoting alternate forms of transportation and improving 30-A and other roads to make them safer, but we need to be very aware of the practicalities of these proposals and the fact that one of the things that makes this area special is that it is a full-time COMMUNITY, not just a collection of resorts.
I predict that as the Boomers age and the economy improves (and yes, when the airport opens) we will see more and more full time residents living in the area and we need to plan our infrastructure with that in mind.