Issue 051 - International trade - Freight value and truckloads
How many truckloads of U.S. goods are affected by Canada's new tariffs?
Canada's counter-tariffs took effect September 8 on C$27.6 billion of annual imports from the United States, roughly US$20 billion. The targeted list covers hundreds of products across steel and aluminum, dairy, appliances, agricultural equipment, pulp and paper, plastics, and electronics.
The problem
Estimate the physical volume represented by about US$20 billion in annual U.S. goods affected by Canada's tariffs, expressed as loaded tractor-trailers crossing into Canada each day.
Choose a reasonable average value per loaded truck and estimate what share of the affected goods travels by truck rather than rail, air, water, or another mode.
Then compare the affected truckloads with the total volume of commercial truck traffic across the U.S.-Canada border. Does the policy touch the equivalent of hundreds, thousands, or tens of thousands of truckloads per day?
Because Fermi problems target an order of magnitude, I normally use no more than two significant digits and write most calculations in scientific notation; the Fermi reference explains both conventions.
Before checking sources
Matt's first pass
First, I tried to get an approximate mass of goods. I used two general categories to represent the trade volume: lumber and foodstuffs. Then I tried to estimate the cost of each category per metric ton.
For lumber, I assumed a 12-foot 2x4 costs about $5, and that there are about 56 of them per cubic meter based on the dimensions. That is an underestimate because the boards are not actually 2 inches by 4 inches. I then assumed a density of about 600 kg/m3.
lumber value per m3 ~= 56 boards x $5/board
~= $280/m3
lumber value per metric ton
~= $280/m3 / 0.6 metric tons/m3
~= $475/metric tonFor food, I assumed most food from Canada would be higher-cost products such as beef and processed syrup. I used about $10/lb, or about $22/kg, and then wrote that as about $2,200 per metric ton.
I assumed food might account for one-fifth of the trade mass and lumber four-fifths. That put my weighted average near $800 per metric ton.
average value per metric ton
~= 0.8 x $475 + 0.2 x $2,200
~= $800/metric ton
mass of affected goods
~= $2 x 10^10 / $8 x 10^2 per metric ton
~= 2.5 x 10^7 metric tonsFor truckloads, I started with the assumption that a fully loaded cargo truck could easily carry about 20 tons, but that most trucks would not be completely full. I used an average load of 15 tons.
annual truckloads
~= 2.5 x 10^7 metric tons / 15 metric tons/truck
~= 1.7 x 10^6 trucks/year
monthly ~= 1.4 x 10^5 trucks
weekly ~= 3.4 x 10^4 trucks
daily ~= 4.7 x 10^3 trucksThat is about 1.7 million truckloads per year, or roughly 4,700 per day, if all of the affected trade is shipped by truck. That felt high.
Calibration Score
Matt's Calibration Score: 55 / 100
Higher is better: earn points for accurate pegs, sound models, correct math, and a result close to the sourced answer. The image shows percent full of it: 100 minus the Calibration Score.
Pegs: 20/30. A 15-ton mixed-freight truckload is a strong anchor, and the lumber calculation was plausible. The chosen product mix was not representative of the tariff list, but the recalled physical quantities were useful.
Model: 15/30. Converting trade value to mass and dividing by payload can work, but the first pass followed Canadian goods toward the United States, omitted the share traveling by truck, and represented a diverse U.S. export list with lumber and food.
Math: 0/10. At $22/kg, one metric ton costs about $22,000, not $2,200. That dropped a power of ten at a step that materially changed the estimated mass.
Result: 20/30. About 4,700 truckloads per day is roughly six to sixteen times the 300-to-800 daily range from the freight-value cross-check, near the edge of one order of magnitude high.
Grounding facts
The Government of Canada says the September 8 counter-tariffs apply to C$27.6 billion in products imported from the United States. Reuters describes that as about US$20 billion.
The official list is concentrated in steel and aluminum, dairy, appliances, agricultural equipment, pulp and paper, plastics, and electronics. That is a much broader and generally higher-value mix than lumber and food alone.
The U.S. Bureau of Transportation Statistics reports US$712.8 billion in two-way U.S.-Canada freight during 2025. Trucks carried US$396.8 billion, or 55.7% of the value.
BTS counted 5,267,429 trucks entering the United States from Canada in 2025, about 14,000 per day. The agency does not collect comparable outbound counts, so using a similar number toward Canada gives a rough two-way scale near 29,000 truck movements per day.
Dividing two-way truck freight value by roughly twice the inbound crossing count gives about $38,000 per truck movement, including empty returns. A working range of $50,000 to $100,000 per loaded truck is therefore reasonable, while recognizing that electronics and machinery can carry much more value than paper, food, or metal.
FHWA freight methods use about 15.45 tons per truck for mixed freight, so Matt's 15-ton payload assumption was close. Here, value per load and product mix matter more than payload capacity.
After checking sources
Check and recalibrate
Start with the US$20 billion headline. Use a 50% to 70% truck-mode share around the overall U.S.-Canada benchmark, then bracket loaded-truck value from $50,000 to $100,000.
low truckload estimate
~= $2 x 10^10 x 0.5 / $1 x 10^5 per truck
~= 1 x 10^5 trucks/year
~= 300 trucks/day
high truckload estimate
~= $2 x 10^10 x 0.7 / $5 x 10^4 per truck
~= 2.8 x 10^5 trucks/year
~= 800 trucks/dayA practical midpoint uses 60% by truck and $75,000 per loaded truck:
affected truck freight ~= $2 x 10^10 x 0.6
~= $1.2 x 10^10/year
loaded trucks/year ~= $1.2 x 10^10 / $7.5 x 10^4
~= 1.6 x 10^5
loaded trucks/day ~= 1.6 x 10^5 / 365
~= 4.4 x 10^2The best Fermi answer is therefore roughly 300 to 800 loaded trucks per day, with about 500 per day as a useful center.
That would be about 2% to 5% of the roughly 14,000 daily trucks moving in one direction across the northern border, or around 1% to 3% of estimated truck movements in both directions. The $20 billion headline represents a substantial flow, but not thousands or tens of thousands of affected truckloads every day.
No published dataset directly counts truckloads for this exact tariff list. The range is a transparent inference from the official affected value, observed mode share, crossing volume, and a deliberately broad cargo-value assumption.
Post-check reflection
Matt's reflection
Well, I blew it on this one. First, I got the directionality wrong. I was focused on goods coming to the United States from Canada instead of vice versa. That totally fouled up my estimate for the cost per metric ton of goods.
Next, I blew it on maintaining orders of magnitude for the cost of a ton of food, accidentally dropping it by a power of ten. Again, I estimated way too low on the cost per metric ton.
Ultimately, I ended up with a very high estimated count of truckloads crossing the border. Otherwise, the calculation was structured in the right direction. Interestingly, my answer ended up high but about within an order of magnitude anyway.
Recommended memory peg
For U.S.-Canada freight problems, remember: trucks carry roughly $4 x 10^11 of goods per year, and about 1.4 x 10^4 trucks cross the border per day in each direction. A mixed freight truck carries about 15 tons, but its cargo value can vary by orders of magnitude.
Reader results
Bars show how submitted estimates sort into the answer choices from the gut-check prompt.