At a recent USDOT Summit, I heard Secretary Foxx, citing his agency’s Beyond Traffic report say the population of the US will increase by 70 million people by 2040 and freight will increase by 45%. Why should population increase by some 22% and freight twice as much over this period?
Well, certainly there is a rise in teleshopping, so local logistics will increase. The amount of this is unclear. Currently e-shopping is on the order of (and under) = 10% of retail sales, but it is growing.
There are several aspects of this. There is the shipment from factory to distribution center, from one distribution center to another, and from the final distribution center to the final destination (usually home), the “last mile”. If the total goods consumed remain the same, the first two stages are essentially unchanged.
If the freight delivery system currently covers every street (that is the UPS guy comes down your street once a day, every day), it will continue to cover every street, just with more vehicles dispatched from the dispatch center to the last mile(s), as with more deliveries there will be more trucks dispatched and each truck will have a shorter, but more intensive route. Ignoring automation in this field (and surely there will be some), once the appropriate optimizations are made in terms of grouping shipments, this still has to be more efficient than individuals going out and coming back from shopping trips.
Shopping trips declining counts as a reduction in personal travel, and UPS shipments count as an increase in freight, but how much is this? Shopping is less than 10% of personal travel.
We might also see a delivery system covering every street twice a day, or four times a day, as real-time deliveries become more significant. I am skeptical Amazon Prime Now – type services will be a thing for most people most of the time (really, I can wait for my lightbulb if it saves some money), but nevertheless if those trucks are not optimally filled, it would increase total freight ton-miles.
There is then the question of whether more material will be consumed overall. My sense is that total matter shipped should decline on a per capita basis. By the time period in question, 2040, the US should be off of coal and oil, replaced with renewable electricity (whose transmission does not count as transportation, unlike coal, oil, or gas). This will decimate the railroad industry, who will then try to move into markets now served by trucks.
Further think about things you use. Many of them are smaller than their equivalent 25 years ago (phones, TVs, computers, cars). Now we may have more of them, and we might need more furniture to occupy our large houses, but that is relatively small in the scheme of things, most freight are things which are consumed daily (food products, energy), not long term capital goods.
We might also increase freight ton-miles if we increase the distances that freight is shipped, but keep the quantity the same. Can our supply chains become even more global? Will they? With automation, the advantages of cheap labor in the production system will diminish, and it will be easier to manufacture locally (to reduce transportation costs and make just-in-time more viable). With cheap energy, things that are now difficult and expensive (like growing exotic fruits and vegetables indoors) will become more viable.
The net is uncertain, we cannot know whether freight shipments will grow faster or slower than population, but to predict, nay assert, a 45% increase is an assumption that should be pushed back on. It is used to justify government investments in highways (and ports and railroads to a lesser extent) for freight that can no longer be justified based on rising per capita passenger travel.