The level of for-hire freight shipments in April measured by the Freight TSI (136.3) was 3.1% below the all-time high of 140.6 reached in August 2019 (Table 2A). BTS’ TSI records begin in 2000. See historical TSI data.

BTS will release the passenger and combined indexes for April next month, because of the difficulty in estimating air passenger travel. Air passenger travel continues to deviate from regular seasonal patterns as it adjusts to the effects induced by the COVID-19 pandemic. The March passenger and combined indexes are available on the BTS website.

Air freight for April is a statistical estimate. Since air freight makes up a small part of the freight index, BTS releases the freight TSI with the air freight estimate in every release.

The Freight TSI measures the month-to-month changes in for-hire freight shipments by mode of transportation in tons and ton-miles, which are combined into one index. The index measures the output of the for-hire freight transportation industry and consists of data from for-hire trucking, rail, inland waterways, pipelines and air freight. The TSI is seasonally-adjusted to remove regular seasonal movement, which enables month-to-month comparisons.

Analysis: The Freight TSI decreased in April due to seasonally adjusted decreases in air freight, rail intermodal, water, and trucking, while rail carload and pipeline increased.

The April decrease occurred in the context of mixed results in other indicators. The Federal Reserve Board Industrial Production (IP) Index was unchanged in April, reflecting decreases of 0.4% in manufacturing and 0.3% in mining, while utilities was up 3.3%. Housing starts were up 1.6% while Personal Income increased by 0.8%.

The Institute for Supply Management Manufacturing (ISM) index fell 0.3 percentage points to 48.7, indicating contraction. A reading above 50 indicates an expansion of U.S. manufacturing, while a reading below 50 indicates a contraction.

Although the April Passenger TSI is being withheld due to the previously cited difficulty of estimating airline passenger travel, the March index is now being released. The index grew by 2.0% from February to March. Seasonally adjusted air passenger, transit and rail passenger all grew.

The Passenger TSI has now exceeded its level in March 2020 —the first month of the pandemic— since May 2021 but remains below its pre-pandemic level (February 2020)..

Trend: The April freight index decrease was the third decrease in four months and the fifth decrease in eight months, leaving the index 2.1% below its level in August 2024. The index increased 3.5% since August 2021, which was a low point after the pandemic surge. The April Freight TSI exceeds the pandemic low in April 2020 by 10.2%; the index increased month-over-month in 35 of the 60 months since that low. 

For additional historical data, go to TSI data.

Index highs and lows: For-hire freight shipments in April 2025 (136.3) were 43.6% higher than the low in April 2009 during the recession (94.9). The April 2025 level was 3.1% below the historic peak (since 2000) reached in August 2019 (140.6).

Year to date: For-hire freight shipments measured by the index were down 0.5% in April compared to the end of 2024 (Table 3).

Long-term trend: For-hire freight shipments are up 10.2% in the five years from April 2020 and are up 12.1% in the 10 years from April 2015 (Table 5). 

Same month of previous year: April 2025 for-hire freight shipments were up 0.7% from April 2024 (Tables 4, 5).

The TSI has three seasonally-adjusted indexes that measure changes from the monthly average of the base year of 2000. The three indexes are freight shipments, passenger travel and a combined measure that merges the freight and passenger indexes. See Seasonally-Adjusted Transportation Data for numbers for individual modes. TSI includes data from 2000 to the present. Release of the May 2025 index is scheduled for July 10, 2025.

Revisions: Monthly data has changed from previous releases due to the use of concurrent seasonal analysis, which results in seasonal analysis factors changing as each month’s data are added.    

BTS research has shown a clear relationship between economic cycles and the Freight and Passenger Transportation Services Indexes. See a study of this relationship using smoothed and detrended TSI data. Researchers who wish to compare TSI over time with other economic indicators, can use the FRED database, which includes freight, passenger and combined TSI, and which makes it possible to easily graph TSI alongside the other series in that database. See TSI data on FRED.   

For charts and discussion on the relationship of the TSI to the economy, see Transportation as an Economic Indicator: Transportation Services Index.

A BTS report explaining the TSI, Transportation Services Index and the Economy, is available for download.

Table A: Summary of Revisions to Freight TSI in Previous 12 Months

Brief Explanation of the TSI  

The Transportation Services Index (TSI) is a measure of the month-to-month changes in the output of services provided by the for-hire transportation industries.  The freight index measure changes in freight shipments while the passenger index measures changes in passenger travel.

The TSI tells us how the output of transportation services has increased or decreased from month to month. The index can be examined together with other economic indicators to produce a better understanding of the current and future course of the economy.   The movement of the index over time can be compared with other economic measures to understand the relationship of changes in transportation output to changes in Gross Domestic Product (GDP).

The freight transportation index consists of:

For-hire trucking,

Railroad freight services (including rail based intermodal shipments such as containers on flat cars),

Inland waterways transportation,

Pipeline transportation (including principally petroleum and petroleum products and natural gas), and

Air freight.

The index does not include international or coastal waterborne movements, private trucking, courier services, or the US Postal Service.

The passenger transportation index consists of:

Local transit,

Intercity passenger rail, and

            Passenger air transportation.

The index does not include intercity bus, sightseeing services, ferry services, taxi service, private automobile usage, or bicycling and other non-motorized transportation.

The TSI includes only domestic "for-hire" freight and passenger transportation. For-hire transportation consists of freight or passenger transport services provided by a firm to external customers for a fee. The TSI does not include taxi services, paid ride services in personal motor vehicles (e.g., Uber, Lyft, etc.), intercity bus services, in-house transportation (vehicles owned and operated by private firms for their own use), or noncommercial passenger travel (e.g., trips in the household car).