The level of for-hire freight shipments in December measured by the Freight TSI (139.1) was 1.3% below the all-time high of 141.0 reached in August 2019 (Table 2A). BTS’ TSI records begin in 2000. See historical TSI data.

The November index was revised to 137.8 from 138.6 in last month's release.

BTS will release the passenger and combined indexes for December 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 November passenger and combined indexes are available on the BTS website. Air freight and waterborne for December are also statistical estimates. Since they make up a smaller part of the freight index, the freight TSI is being released as scheduled with the estimates 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 increased in December due to seasonally adjusted increases in air freight, rail carload, rail intermodal and trucking, while pipeline and water declined.

The December increase came in the context of mixed results for some other indicators. The Federal Reserve Board Industrial Production Index increased 0.1% in December, reflecting increases of 0.9% in mining and 0.1% in manufacturing while utilities fell 1.0%. Personal income increased 0.3 while housing starts were down 4.3%.

The Institute for Supply Management Manufacturing index for December increased 0.7 points to 47.4, indicating manufacturing is continuing to contract but at a slower pace (a manufacturing index above 48.7 percent, generally indicates an expansion of the overall economy).

Although BTS withheld the December Passenger TSI because of the previously cited difficulty of estimating airline passenger travel and other components, the November index is now being released. The index increased 0.6% from October to November. Seasonally adjusted air passenger was unchanged, while rail passenger and transit grew.

The Passenger TSI exceeded its level in March 2020 —the first month of the pandemic— for 30 months in a row but remains below its pre-pandemic level (February 2020) for the 45th consecutive month.

Trend: The December freight index increase followed a decrease in November and was the fifth increase in six months, leaving the index 1.6% above the June level. The index increased 3.8% since August 2021. The December Freight TSI exceeds the pandemic low in April 2020 by 12.1%; the index increased month-over-month in 26 of the 44 months since that low. The index remains 1.4% below its previous record level of 141.0 set in August 2019, despite increasing month-over-month in 26 of the 52 months since that all-time high.

For additional historical data, go to TSI data.

Index highs and lows: For-hire freight shipments in December 2023 (139.1) were 46.4% higher than the low in April 2009 during the recession (95.0). The December 2023 level was 1.3% below the historic peak (since 2000) reached in August 2019 (141.0).

Year to date: For-hire freight shipments measured by the index were up 1.8% in December compared to the end of 2022 (Table 3).

Long-term trend: For-hire freight shipments are up 0.9% in the five years from December 2018 and are up 18.1% in the 10 years from December 2013 (Table 5).  

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

4th quarter changes: The freight TSI rose 0.5% in the 1st quarter, fell 0.4% in the 2nd quarter, rose 1.2% in the 3rd quarter, and rose 0.4% in the 4th 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 January 2024 index is scheduled for March 13, 2024.

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

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.
NOTE: The entire Freight TSI is revised monthly. Changes shown only for the previous 12 months. 
 

Table 1: Freight Transportation Services Index since June 2023 
Percent Change from Previous Month
(Seasonally Adjusted, Monthly Average of 2000 = 100)

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.
NOTE: Percent changes based on numbers prior to rounding. 
 

Table 1A: Annual High and Low Points in Freight Transportation Services Index, 2009-2023 

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.
NOTE: The unrounded level in August 2019 (141.0295) was slightly higher than that of August 2022 (140.9997). The relative levels of these two months have reversed from the last TSI release due to revisions.  
 

Table 2: Freight Transportation Services Index Monthly Changes, 2020-2023
Percent change from previous month

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

Table 2A: Freight Transportation Services Index by Month, 2020-2023

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

Table 3: Freight Transportation Services Index Year-to-Date Change, 2014-2023
Percent change to December from December of the previous year

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

Table 4: Freight Transportation Services Index from Year-to-Year
Percent Change in the December Freight TSI 
(Monthly average of 2000 = 100)

SOURCE: Bureau of Transportation Statistics. See Transportation Services Index for documentation, data and other background information.
NOTE: Percent changes based on numbers prior to rounding.
 

Table 5: Freight Transportation Services Index from Previous Years 
Percent Change to 2023 (December to December)

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).