[jester]

Regular daily traffic, no of course not. But it is still a line of communication. And lets not forget that the 15 is a route that many early settlers took on foot and in wagons, so I can see caravans making the route.

As for the I-5, easily done, that is a desert? Dang never even thought of it as such. Again it could be done easier than the 15.

They simply put up watering stations. At wells, as well as water tanks and have a team of mules like the old Borax mule teams, but instead of hauling ore, they haul water tanks to refile the watering stations.

Then the state/gov or whatever entity charges a toll for using that section of the 15 to include the use of water, which is the main reason for the toll, they pay by the head. And the local government entity bars anyone from traveling who does not have a good working vehicle with the fuel and water to make the trip.

And we could see a monthly caravan, actualy 2 caravans one going each way transering mail, the ocasional passenger and trade goods. Again it would be similiar to the Butterfield and Wells Fargo stage lines that plied their way between San Bernardino and Arizona and Utah in the 19th Century

As for coastal travel, I would not even thing the Pacific Coast Highway would be totaly passable after 3 years due to flooding, erroson and rockslides. Large segements would surely be open and passable, but the entire route hardly. Some areas near communities whose interest would be best suited in keeping it open would maintain it, but other sections would fall into disrepair.

But, you forget 1 other route,

A sea route! That was the normal means of transport well into the early years of the 20th century. Larger sailboats 30+ feet would be a easy rapid and realativly safe transportation route up and down the coast. It is not that hard with working compass, modern charts and if one is warry of storms taking care to avoid sailing to far out to sea or durring storm season.