Japan plans ‘conveyor belt road’ linking Tokyo and Osaka amid delivery driver shortage

My guess is it must be at capacity and there's no space to build a parallel lane next to the tracks. This is conveyor belt so it is constantly moving in both directions with pellets being dropped back and forth. Of course rail industry has been trying to get to the "conveyor belt" idea for sometime but to have one that's constantly moving both directions isn't executable.

The existing rail network is already pretty jammed on a lot of lines. Cargo does run at night (mostly) on other rail lines, but night is when maintenance is also done (we don't really have any 24-hour trains here except on special occasions and I think none of those even since corona). The safety record here does come with a cost in that sense; the checks, maintenance, and construction all occur at night with freight running around that.

If they are adding this in the middle of the expressways, the land is already acquired. It probably takes less infrastructure to do this than putting in rails would involved. I also doubt it would be to code for rails since there needs to be room to get passengers off in the case of emergency, etc. Zooming in on 35.698190871019335, 139.75230458261458 in Tokyo does show there isn't even really any room between lanes, though, and it's not different up where I live a few hundred KM north so I'm not exactly sure what the play is. All expressways are paid today and the tolls were supposed to go away eventually, but they never will if the construction never ends (and it never ends).

Can't figure out how to make chain signals work

Probably to have a short quotable one liner that's vaguely understandable by the general public (and that, as often, is false).

Keep 'em rolling!

First friggin' paragraph....

Six decades after the bullet train first whisked passengers between Tokyo and Osaka, authorities in Japan are planning to do the same for cargo, with the construction of a “conveyor belt road”.

I don't know why OP is getting downvoted. This comment is correct. The economies of freight on rails are predicated on scale. The bigger the train, the better. It only requires a few locomotives that have the biggest maintenance costs. Cars are unpowered and require less maintenance. A train can transport thousands of tons. An average mid-size train in Europe would carry about 2000 tonnes of freight.

To add an electric motor per ton of cargo transported (as detailed in the article) adds an excessive amount of overhead costs to the cargo transported, in upfront costs, maintenance and environmental impact, making it less competitive than a regular freight line. With the space of the same infrastructure and probably the same investment, you could instead run a freight line, especially considering the distance between Osaka and Tokyo. Over time, the freight line wins out over the individual one ton self-propelled cargo wagons. Remember, every propulsion system breaks down and requires new parts and fixing. The more of them there are, the more complex your transportation system becomes, thus more expensive. An equivalent to a mid sized freight train in pods would require about 2000 electric motors, as opposed to one or two dedicated electrical locomotives.

They should instead improve the trains to be able to run mostly automated. This requires track sensors and advanced signaling.