Population growth includes more hauling by truck. And it’s ripping our roads apart.
America now has 308 million people, up from 200 million in 1968 and 150 million in 1950 – which was about the time we started building most of our roads. This growth is about more than just people driving around in cars. It’s about all our things – the stuff that goes into making the stuff, and the transport of the end-product stuff from factories (or ports) to warehouses and stores where we buy the stuff – and how those things get to us. Add to that the garbage trucks that haul those things away after we’re done with them.
Those roads were built in the 1950s, 1960s and 1970s mostly to handle cars, the nice one-ton two-axle vehicles that went by names like Buick, Oldsmobile, Studebaker and Pontiac. The cargo was dad and mom going to work, or kids going to ball games, maybe vacation luggage stuffed with shorts and flip flops and a happy dog poking his nose out an open window. That was when we could see the U.S.A. in a Chevrolet.
There was freight shipping then, just as there is freight shipping now. Back in 1950, the majority of freight traveled by rail. Once it got to the station closest to its destination, it was offloaded into short-haul trucks and sent on its way.
But since the development of the Interstate Highway System, freight shipping has gradually migrated away from rails to surface transportation. Today, upwards of 560,000 for-hire and private carriers command 88 cents for every dollar spent on shipping (about 65 percent of all freight by weight). The U.S. Department of Labor reports that 3.24 million people are employed as truck drivers today, with the long-haul drivers averaging more than 100,000 miles driven per year.
That’s a lot of trucks, a lot of weight – and heavy commercial dependency on roads.
There are many voices (particularly from the rail industry itself) offering reasons why we need to shift how freight is hauled, from trucks back to railways:
- Freight railways are energy efficient by a factor of three over trucks, moving one ton of freight about 400 miles on a single gallon of fuel.
- Freight railways are less polluting, emitting one-third as much in nitrogen oxides as a truck for every ton-mile traveled.
- Freight railroads alleviate highway congestion, replacing between 280 and 500 trucks with a single intermodal train. Considering lost time in traffic, this amounts to an “inefficiency tax” on all other highway users.
- Transportation by rail is safer, particularly when hauling hazardous materials. The two modes cumulatively carry an equivalent amount of hazmat ton-miles, but the record shows that trucks accidentally release16 times more hazmat than do railways.
The favorable economics of truck freight are inarguable, however. It is frequently cheaper to ship from point A to point B with a truck, eliminating the intermodal transfers from local-haul truck to train, then from train back to a truck nearest the point of destination. Time is money, particularly in a just-in-time manufacturing and retail world. Trucks allow a degree of speed and control of schedules that the railways can only approximate.
How heavy vehicles lead to potholes
One cost that is not factored into shipping is how roads and bridges suffer greater damage from truck traffic. A 5700-pound Cadillac Escalade (or a 1600-pound Smart Car) does not cause the same damage as an 80,000-pound Peterbilt Truck.
To be fair, the 80,000-pound trucks (plus cargo) distribute their weight over 18 wheels. Averaged, that would be 4444 pounds per wheel. But the steering (front) wheels bear a lesser portion of the load, while many of those wheels are side by side and the front wheels are quickly followed by the back wheels. And even on the Cadillac Escalade, the per-wheel load is about 1425 pounds.
It amounts to road damage, borne not just by the federal highways but also state, county and city roads and streets. For example, the municipality of Hayden, Idaho Department of Public Works exerts its authority to restrict vehicle size, weight and speed for the protection of roads and public safety. The Hayden website explains exactly why it has vehicle load restrictions during the winter months:
“The moisture found in the soils and gravels below a road’s surface freezes. The depth of this frost zone varies depending upon the length and severity of the winter season. This frozen zone begins to thaw from the surface down, at varying rates. The moisture released by the thawing soils and gravels is trapped near the surface between the pavement and frozen soil below. When this occurs, the overhead passage of heavy equipment can create a “bouncing” or “pumping” effect on the trapped moisture layer, and can severely damage the roadway’s structural integrity and significantly decrease its lifespan.
Spring breakup restrictions are required to mitigate this characteristic seasonal freeze/thaw cycle, which makes the roadway unstable and reduces its load-bearing capacity. These load restrictions are weather dependent – not calendar based. Such restrictions are normally required throughout the spring breakup season that can start as early as February and extend into May.”
As with almost all states and municipalities, weight limits on vehicles are policed, including with weigh stations. However, emergencies and construction periods allow for special circumstances – in Hayden that includes, “in the event of power outages or other damaged utilities, those utilities shall be exempt from the weight restrictions.” In another example, the California Department of Transportation allows weight exemptions for trucks transporting livestock, dump trucks, cranes, cement trucks adjacent to job sites and trucks transporting garbage, among others.
Weighs the same, uses less gas – and road maintenance funds drop
To cover their tracks, so to speak, trucks also are required to pay a larger share in vehicle use taxes. On average this amounts to about $16,000 per vehicle per year in licensing and usage fees. It includes the heavy vehicle use tax, paid to the Internal Revenue Service for all vehicles weighing 55,000 pounds or more (graduated by size with an annual cap of $550). Additionally, the trucking industry bears the higher federal per-gallon tax rate (24.4 cents per gallon for diesel fuel, compared to 18.4 cents for regular gasoline), plus a tax on tires that is pegged to the overall size (weight) of the tire, into the federal Highway Trust Fund (HTF).
Currently, the HTF provides about a third of the total amount needed to bring our roads back to good service. The Fund provides about $90 billion but $224 billion to $340 billion is needed for adequate infrastructure maintenance.
The looming, new problem is how improving fuel use efficiencies in trucks and all other surface transportation translate into lower gas tax revenues. Everyone wants to see a reduced dependence on fossil fuel use, particularly from foreign-sourced petroleum. And great strides are being made in this area, both with cars and trucks. But with 40, 50 and 60 year old roads crumbling, and limited public funds available to fix them, there is great uncertainty how those highways and byways will be maintained.
It does not appear as if surface transportation will soon go away. Until the economics of rails beats out the roads, we are likely to see continued use, perhaps expanded use, of trucks to move goods.
But that assumes the roads can be maintained to a useable degree. Given the decline in road maintenance funding, it is unclear if that can actually happen.