Trucks do not have a 35 ton/axle cargo! They have 35 tons cargo, and 5-6 axles...
In logistics, you could perhaps imagine a HSR line between two important nodes (like Paris/Lyon/Marseille in France), taking trucks on a no booking, shuttle basis so as to lower the community costs of road repairing - which is actually a government indirect subvention, at least in Europe-. Thus, road and train transport would compete on a same cost basis... which is conform to economic doxa. A free fox in a free henhouse!
The axle loading is for the rail car ... and, yes, if there is a Freight Express rail clearway, with those axle loading
Designing a High Speed Freight Rail set that takes whole trucks is, for one thing, hauling weight around unnecessarily, magnifying the extra energy cost of HSFR over Express Freight Rail, and, for another thing, the job of trucks should be to haul a container the last mile to from the railhead to the final street address or warehouse ... the extension of the HSFR should be the load racking into a standard container to go to that closest railhead. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
