Jacksonville, FL to Amelia Island

[DR]

I hope to bike all or part of the east coast of Florida in late April to early May. I plan to take a train to Jacksonville then bike to Fernandina Beach to start. Does anyone have any advice on routes from the Amtrak station to Amelia Island? The obvious (but not shortest) route seems to be northwest on US 1 to A1A at Callahan, then east. But I’d like to know if there are other routes that are shorter and preferable. I’d like to approach Amelia Island from the west (rather than the south), if possible, to minimize covering that same section of the coast twice. Thank you!

[CMajernik]

Do you have the Atlantic Coast Route section 6 map? From Jacksonville, if you go to Callahan and head east to Fernandina Beach the route then takes you south along the coast so you wouldn't be doing any backtracking. Due to the rivers in the area you can only approach Fernandina Beach from the west or south.