"Least amount of car traffic"

[BikePacker]

A sorta outside the box trans am to accomplish max safety/min. traffic + most fun route selection cycling:
Employ 'Longitude Linking.'

I can also see it being a transportation nightmare given that the goal is to get to traffic free places not major cities ... but it may be someone's cup of tea.

Fits best with the tourist who is already anticipating going coast to coast in multiple sections/legs,
wherein transportation/logistics to & from multiple start and stop points is already baked into the methodology.

Which raises a long time curiosity in my mind
(not to get off Original Post target - and may well be addressed elsewhere/somewhere on the Forum)...
have long time wondered how many folks that do make it coast to coast do so in a mostly end to end/thru all at once tour
in comparison to how many folks accomplish it in multiple sections/legs.

[staehpj1]

Which raises a long time curiosity in my mind
(not to get off Original Post target - and may well be addressed elsewhere/somewhere on the Forum)...
have long time wondered how many folks that do make it coast to coast to so in a mostly end to end/thru all at once tour
in comparison to how many folks accomplish it in multiple sections/legs.

Based only on the folks I met when on the road, I'd say the majority do it all in one go.  Followed by a few who broke it down into two sections in two different years.  I didn't meet anyone who was doing it in smaller chunks, but maybe they just didn't mention what they were doing.  The ones doing it in two chunks were mostly folks who stopped because of a health problems or had other unplanned reasons for stopping.  Two different guys stopped with a cancer diagnosis and came back later to finish and a friend broke an arm in a fall on a wet road and went back the following year to finish the last several hundred miles.  One guy flew home because of a family emergency and finished another year.

I didn't really finish the ST, but considered it a coast to coast ride since I made it to Pensacola Florida and the Gulf is East Coast enough for me.  I might have felt differently if I hadn't already scratched the coast to coast itch by previously riding the Trans America.  Actually, I still I do plan to ride across Florida at some point I was going to do that this Spring if it had not been for the pandemic.  So in a sense, I will kind of be doing one in two sections, but I really don't think of it as completing a coast to coast ride when I do ride across Florida.

[misterflask]

On short tours, I've recently been using Google cycle routing on my smartphone.  It results in interesting routes and generally low traffic.  The things I've stumbled on have been a delight.  If I see a road that looks interesting, I turn down it and let Google figure it out from there.  Coverage is generally good where I've been, but there have been a few spots of absent coverage that added interest to the process.

[staehpj1]

On short tours, I've recently been using Google cycle routing on my smartphone.  It results in interesting routes and generally low traffic.  The things I've stumbled on have been a delight.  If I see a road that looks interesting, I turn down it and let Google figure it out from there.  Coverage is generally good where I've been, but there have been a few spots of absent coverage that added interest to the process.

I often look at both the Google car and bike directions.  I choose the car directions more often than the bike directions, but sometimes there are real gems well worth checking out in the bike directions.  Other times they seem to go way out of their way to use a MUP that I'd just as soon avoid.

[TCS]

While I'm fine riding on city streets to get out into the country at home, or riding through towns and (small) cities on tour, I've encountered other cyclists who seem traumatized by the experience.

I recall we had the poster here on this forum recommend that when riding long-distance routes, one was best served by riding no further than the city limit of urban areas and calling Uber or Lyft for transport to the far side to continue the cycle tour.  Well, everyone has their personal experiences, knowledge base and skill set, and hey, you like what you like.

It's funny, though.  In my neck of the woods there are traffic-phobes who are raising money to create future rail-trails, while the USBRS folks in my state won't consider the future designation of anything but highways with shoulders as a state bike route.  The reality on the ground is we have an existing thatch of quiet, paved country lanes that no one is promoting.  Shrug.

[TCS]

In my salad days as a cycle tourist, I would head out 'in a general direction'.  On a couple of occasions, my serendipitous route funneled me onto twenty miles of shoulderless, narrow, high traffic road thirty years past the time it should have been rebuilt, with the flow of motor vehicles at the posted speed limit or above.

I don't seek out routes with the ~least~ traffic, but I take some pains not to repeat those experiences.

[Pat Lamb]

It's funny, though.  In my neck of the woods there are traffic-phobes who are raising money to create future rail-trails, while the USBRS folks in my state won't consider the future designation of anything but highways with shoulders as a state bike route.  The reality on the ground is we have an existing thatch of quiet, paved country lanes that no one is promoting.  Shrug.

At least the USBRS planners near you have the sense to insist on shoulders!  The southern end of one USBRS near me ends with a five-mile jog to ride a U.S. highway with a lot of traffic but without shoulders for some 3-4 miles to the state line.  Uphill.  I tried it once, and I've sworn not to risk my life on it again.  I'll stay on the not-quite-zero traffic road climbing the same escarpment that has shade.