The level of for-hire freight shipments in September measured by the Freight TSI (138.6) remained 1.8% below the all-time high level of 141.1 in August 2019 (Table 2A). BTS’ TSI records begin in 2000. See historical TSI data.

The August index was revised to 138.6 from 138.5 in last month's release.

BTS will release the passenger and combined indexes for September next month, because air passenger travel continues to deviate from regular seasonal patterns, as it adjusts to the effects induced by the COVID-19 pandemic. The August passenger and combined indexesare available on the BTS website. Air freight for September is also a statistical estimate. Since air freight makes up a smaller part of the freight index, the freight TSI is being released as scheduled with the air freight estimate included.

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 remained unchanged in Septemberdue to seasonally adjusted increases in pipeline, rail intermodal and rail carload, while air, water, and trucking decreased.

The September result came in the context of positive results for other indicators. The Federal Reserve Board Industrial Production (IP) Index increased 0.3% in September, reflecting increases of 0.4% in manufacturing and 0.4% in mining while utilities decreased 0.3%.Housing starts and personal income increased7.0% and 0.3%, respectively.

The Institute for Supply Management Manufacturing (ISM) index increased 1.4 points to 49.0, indicating a return to modest growth in manufacturing.

Although BTS withheld the September Passenger TSI because of the previously cited difficulty of estimating airline passenger travel and other components, the August index is now being released. The index increased 1.4% from July to August.Seasonally adjusted air passenger, transit, and rail passenger all grew.

The Passenger TSI exceeded its level in March 2020 —the first month of the pandemic— for 27 months in a rowbut remains below its pre-pandemic level (February 2020) for the42nd consecutive month.

Trend: The Septemberfreight index result followed four increases in a row, leaving the index 1.9% above the April level but 0.9% below February.This left the index 1.8% below its level in August 2022. The index increased 3.3% since August 2021.The September Freight TSIexceeds the pandemic low in April 2020 by 11.7%; the index increased month-over-month in 23 of the 41 months since that low.The index remains 1.8% below its previous recordlevel of 141.1 set in August 2019, despite increasing month-over-month in 23 of the 49 months since that all-time high.

For additional historical data, go to TSI data.

Index highs and lows: For-hire freight shipments in September 2023 (138.6) were 45.9% higher than the low in April 2009 during the recession (95.0). The September 2023 level was 1.8% below the historic peak (since 2000) reached in August 2019 (141.1).

Year to date: For-hire freight shipments measured by the index were up 1.3% in September compared to the end of 2022 (Table 3).

Long-term trend: For-hire freight shipments are up 0.1% in the five years from September 2018 and are up 18.8% in the 10 years from September 2013 (Table 5). 

Same month of previous year: September 2023 for-hire freight shipments were down 1.8% from September 2022 (Tables 4, 5).

3rd quarter changes: The freight TSI rose 0.4% in the 1st quarter, fell 0.4% in the 2nd quarter, and rose 1.3% in the 3rd quarter (Table 10).  

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 October 2023 index is scheduled for December 6, 2023.

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.

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.

Table 6: Freight Transportation Services Index Change by Quarter, 2014-2023
Percent change from the last month of the previous quarter

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.

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).