2022 Highway Subsidies Were 1¢/Passenger-Mile

U.S. highways, roads, and streets received a little over $65 billion worth of subsidies in 2022, according to data recently released by the Federal Highway Administration. Apportioning these subsidies to passengers and freight, they work out to about 1.0¢ per passenger-mile and 0.7¢ per ton-mile. For comparison, subsidies to transit averaged $2.39 per passenger-mile while subsidies to Amtrak averaged about 40¢ per passenger-mile.

The Key Bridge in Baltimore collapsed yesterday due to being struck by a ship. If this had happened before 2021, it is likely that some lobby groups would have blamed the collapse on poor maintenance. Such claims led Congress to give the Federal Highway Administration an additional $90 billion, to be spent over six years, in the 2021 infrastructure law.

I calculated the highway subsidy numbers from the Federal Highway Administration’s latest edition of Highway Statistics. The agency once published this report as a book but now issues it as a series of spreadsheets. Earlier this month, I reported on spreadsheets showing the volume of traffic carried on the highways, but the financial spreadsheets were not yet available. Now they are.

Total highway subsidies can be calculated by adding up all of the non-user-fees given to road agencies by federal, state, and local governments, and subtracting from that total the tolls and other highway user fees that are diverted to transit and other non-highway purposes. These numbers are found in table HF-10.

For 2022, table HF-10 says that federal general funds for highways were $90 billion, a substantial increase over the $10 billion in 2021. This is misleading, however, as that $90 billion is meant to be spent over a six-year period. I counted only $15 billion of that amount, and even that may be a bit too high as state agencies were probably not geared up to increase their spending by $5 billion between 2021 and 2022. For the next five years, I’ll add $15 billion to federal spending when using table HF-10 to calculate subsidies.

Table VM-1 says that U.S. highways carried 4.7 trillion passenger-miles in 2022. I don’t count the passenger-miles that the table attributes to heavy trucks, as these represent the drivers, and I wouldn’t count bus or train drivers as passenger-miles carried by transit or Amtrak.

This 4.7 trillion passenger-miles is a sharp drop from the 5.0 trillion reported in 2021 due to a recalculation of automobile occupancy rates. The 2017 National Household Travel Survey estimated the average auto carried 1.67 people but the 2022 survey found this had dropped to 1.52 people. It is likely that this drop was due to the pandemic, which means the lower number should have been applied in 2021, but the Federal Highway Administration continued to use the 2017 number.

To apportion the $65 billion in subsidies to passengers and freight, I add up the total amount spent on automobiles and the total amount spent on highway shipping. Unfortunately, the Bureau of Transportation Statistics has not yet reported ton-miles of freight for 2022, but in previous years, shipping accounted for about 25 percent of expenditures while passenger travel accounted for 75 percent. Three-quarters of the $65 billion divided by 4.7 trillion passenger-miles works out to 1.0 cents per passenger-mile. Assuming 2022 ton-miles were not drastically different from 2020, subsidies to trucks averaged about 0.67 cents per ton-mile.

We don’t yet have enough data to calculate subsidies to air travel, which in previous years averaged about 1¢ per passenger-mile. Based on available data, I estimate this increased to a little over 3¢ per passenger-mile in 2022 due to increased spending on airports and somewhat lower passenger-miles. It is still well below the 40 cents per passenger-mile Amtrak subsidies.

While highway subsidies averaged a penny per passenger-mile nationwide, subsidies can vary greatly by state. Using the same formula as at the federal level, state and local highway subsidies can be calculated by subtracting the diversions of highway user fees to transit and other non-highway purposes from the non-user fees spent on roads. Tables SDF and LDF report state and local diversions of user fees to other purposes while tables SF-3 and LF-1 report state and local non-user-fees spent on roads.

In an Antiplanner policy brief, I estimated the state subsidies and the local subsidies per vehicle-mile for each state. To do so, I had to estimate how much travel was done on state highways and how much on local roads. For today, I’ll just estimate the total of state and local subsidies by state.

Highway Statistics doesn’t show how much traffic in each state is trucks vs. autos. Auto occupancy rates also vary by state — they will be higher in states with larger family sizes — but those data aren’t available either. The subsidies per passenger-mile assume 1.52 occupants per vehicle and that 25 percent of total subsidies are attributable to freight. The numbers shown only include subsidies from state & local governments; federal subsidies, which averaged about 0.2 cents per passenger-mile, are not included.

California and ten other states divert so much out of gas taxes and other highway user fees to non-highway uses that subsidies in those states are negative. Subsidies tend to be greatest in states like Alaska and Wyoming that have lots of roads but not many people to drive on them. An average of 94 percent of the state and local subsidies are from local governments because most local governments have limited abilities to charge tolls, fuel taxes, or other user fees.