It's mostly 2 lanes. There are some 4 lane areas but the speed is max 55 and mostly 35-45. It's a pleasant drive with great views. Depending on where you're staying here's a few of our favorite places to eat.
Marathon: Lazy Days on the water good sunsets great food and happy hour
Big Pine: Buck Tail Roosters and the No Name PUB..best pizza in the Keys
Sugar Loaf Key: Mangrove Mamma's good bands and great seafood
Stock Island: Hog Fish Grill
Key West: Grands on Duval St OMG and Commodores at the marina best happy hour in Key west and inexpensive at happy hour.