I've created two .list files covering
all american roads and
national scenic byways (which also has the AARs). I've not yet gone and fixed the nsb file (I've spent far too much time on this this week already), and there's a lot more of them and they are lower-status, so lets just look at the All American Roads:
Here's the status of each AAR in the browser.
green means it's all there,
blue means less than 10 miles is missing,
orange means more than 10 miles is missing, and
red means none of it is there.
- A1A Scenic & Historic Coastal Byway
- Acadia All American Road (missing about 350ft between Paradise Hill Road and ME3 (not worth bothering with adding, IMO))
- Alaska's Marine Highway (is all ferries)
- Beartooth Highway
- Blue Ridge Parkway
- Chesapeake Country Scenic Byway
- Chinook Scenic Byway (Stephen Mather Memorial Parkway)
- Colonial Parkway
- Creole Nature Trail (missing 7.5 mile section along PR357)
- Flaming Gorge - Green River Basin Scenic Byway
- Florida Keys Scenic Highway
- George Washington Memorial Parkway
- Great River Road (note that Missouri and Mississippi sections are not 'All American Road')
- Harriet Tubman Underground Railroad Byway
- Hells Canyon Scenic Byway
- Historic Columbia River Highway
- Historic National Road
- Historic Route 66 - Arizona
- Historic Route 66 - Missouri
- International Selkirk Loop
- Lakes to Locks Passage (some maps show it keeping to the mapped routes, rather than taking the local ones at the missing gap)
- Las Vegas Strip (unsigned NV state route)
- Natchez Trace Parkway
- Newfound Gap Road Byway
- North Shore Scenic Drive (missing 2.9 miles section in Duluth)
- Northwest Passage Scenic Byway
- Pacific Coast Scenic Byway
- Red Rock Scenic Byway
- Route 1, Big Sur Coast Highway
- Route 1, San Luis Obispo North Coast Byway
- San Juan Skyway
- Selma to Montgomery March Byway (missing 0.7 mile section in Selma and 5 mile section in Montgomery)
- Utah's Scenic Byway 12 - A Journey Through Time
- Seward Highway
- The Battle Road Scenic Byway (could this be added to usanp? It seems to be something closely linked to Minute Men NHS)
- Trail Ridge Road/Beaver Meadow Road
- Volcanic Legacy Scenic Byway
- Woodward Avenue (M-1) - Automotive Heritage Trail (missing 0.5 mile section in downtown Detroit)
Making separate routes for some of the green routes, where they run on several different routes, might make sense. But stuff like Route 1 in California, or Utah 12, is obviously duplication. And you also have stuff like Beartooth Highway (just US212), Pacific Coast Scenic Byway (just US101), or Florida Keys Scenic Highway (just US1). So even if we add routes, the likelihood of a full usaar system is low because there's so much duplication.