10 March 2016 - DrSunshine.org


Most of our stuff is moved around by trucks. They're very convenient because they can pick up and deliver stuff just about anywhere, and the stuff only needs to be loaded and unloaded once. Stuff moved by trains usually needs to be loaded and unloaded at least twice, which takes extra time and money. Plus, most truck drivers are pretty good citizens on the road. Safe drivers, mostly, and even good Samaritans sometimes. So, trucks are convenient and nice to have around, but what does it cost?

Most roads are designed, constructed, and maintained at public expense through federal, state, and local taxes and fees. Trucking companies pay some of that through registration fees, fuel taxes, turnpike tolls, and the like. Ordinary citizens pay, too, in more or less the same way. Big trucks are, of course, a lot heavier than cars, so roads have be sturdy enough to handle truck traffic. That makes roads more expensive to build and maintain than if the traffic were limited to cars. But how much more expensive? That is the question Dr Sunshine wants to address.

To keep things as simple as possible, let's focus on road maintenance. It would be nice to factor in road construction costs, too, but analyzing the maintenance picture turns out to be plenty difficult, and Dr Sunshine ran out of energy just tracking down those figures.

The wear and tear a vehicle imposes on a road depends on a lot of things. Vehicle weight is one factor, but the number of wheels a vehicle has, road surface and substrate, and even minor things like distance between axles and air pressure in tires also play a role. Engineers use ESAL (equivalent single axle load) as a road design gauge. Vehicles with large ESAL numbers require studier roads and cause more wear and tear in transit than vehicles with smaller ESAL numbers. ESAL can be estimated from the weight of a vehicle and the number of wheels it has. It is roughly proportional to the number of wheels multiplied by the fourth power of the average weight per wheel, but ESAL tables provide better figures by taking other factors into account.

The ESAL for a loaded semi (80,000 lbs, 18 wheels) is about 1500 times the ESAL for a typical pickup truck (6,000 lbs, 4 wheels). So, suppose you're driving behind a semi when you come to a toll booth. Let's say the semi pays a toll of $15. Since your pickup causes 1500 times less wear and tear on the road, you should pay a toll of $0.01, at most ($15 divided by 1500 ESAL). But you don't. When the semi pays $15, you pay $2.50 to $5.00, depending on what state you're in. It's worse if you're driving a compact car (3,500 lbs, 4 wheels, and an ESAL 3,000 times less than a semi). No matter what, you're getting monumentally ripped off on toll roads.

What about highways without tolls? Those are harder to figure out because the data is hard to come by. According to traffic studies Dr Sunshine looked at, heavy trucks (18 wheels or more) comprise 10% to 15% of the total annual mileage driven on highways in the USA. (The trucking industry itself puts the figure at around 14%.) Ordinary cars and pickups account for most of the rest. To be more than fair, let's say big trucks are only 10% of the traffic and pickups, which are relatively heavy for passenger vehicles, make up the remaining 90%.

Because of the relative ESALs of heavy trucks and pickups, you have to multiply heavy truck traffic by 1500 when you compute the percentage of road wear attributable to heavy trucks. That's 1500 times 10% divided by that figure plus the road wear due to pickups, which is 1 times 90%. Go ahead. Compute. You will find that over 99% of the road wear is attributable to heavy truck traffic. In other words, when it comes to highway maintenance, cars and pickups don't count. It's just heavy trucks.

The total investment in highways (federal, state, and local) comes to about $218 billion a year. The trucking industry says it pays $37.3 billion a year in highway taxes. But, they should be paying 99% of $218 billion, which is $216 billion. The public is subsidizing the trucking industry to the tune of $178 billion. Trucking industry revenues were about $700 billion in 2014. To pay what they owe, they could take a 25% hit in revenues ($178 billion is about 25% of $700 billion). That would probably put them in the red. Or, they could increase their fees by 25%. That would probably wipe out the convenience factor that Dr Sunshine led with. 

The bottom line is that there is no place for heavy trucks in a rational freight delivery system.

If we were smart, we'd put all the long haul stuff on trains and use small trucks to get the stuff to and from train stations. Stuff that wouldn't fit on small trucks would have to be redesigned to fit. Stuff that couldn't be redesigned to fit would have to be manufactured where it's needed. Or carried there some other way. Blimps? Maybe. (Lockheed is working on it.) But not heavy trucks. If we were smart (and Dr Sunshine would be the last person to claim we are), we'd dump heavy trucks.

Dr Sunshine

Update, 11 Mar 2016: Estimates of trucking industry subsidies in a 2015 CBO report are consistent with those of Dr Sunshine.

email the doctor

© 2016 Dr Sunshine - All rights reserved