This discussion began with comments about artics sharing streets with bikes, and even just the difficulty of getting and artic round narrow streets at all.Jon in Sweden wrote: ↑25 Jun 2022, 9:30pm For reference (regarding pollution):
An artic takes up twice the road space of a 7.5t lorry, uses twice as much fuel, but carries 7 times as much weight.
It is 3.5 times more fuel and space efficient to use artics.
Most of the fuel cost is overcoming air resistance. Frontal area of an artic isn't massively bigger than a 7.5t lorry.
Some contributors raised the idea of transhipping loads into smaller units for distribution.
Your comparisons are about moving complete loads on free moving roads, which is a very different situation. If you want to find the most fuel and pollution efficient way of moving complete loads, rail will come out on top. Aerodynamics are unimportant driving around town.
This comparison has a limited application, not one which would improve our towns and cities.
As PWA points out, big lorries are more suited to the out of town shopping sheds which are convenient for car use but destroy town centres.
I have no car and reaching these places involves more walking and waiting at bus stops (i can no longer cycle). I feel the world is more and more built for the motorised, which is not the way to cut carbon emissions. A compact town centre is much more apt for the unmotorised, and trying to get cars and worse, artics, into it is difficult.
I will soon have another hospital visit, which involves two bus trips each way. The hospital, like the retail sheds, has moved out of town, partly to accomodate the huge car park which i trudge past on my way to the entrance doors. Motorists complain about parking problems! So do hospital workers complain about having to pay for parking. Should buses be free for hospital workers?