BTS is withholding the scheduled release of the passenger and combined indexes for March. The passenger index for March is a statistical estimate of airline passenger travel and other components based on historical trends up to February 2021. The statistical estimate does not fully account for the rapidly changing impacts of the coronavirus on the historical trend. Air freight for March 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 February passenger and combined indexes are available on the BTS website.

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 variation from month-to-month comparisons.

Analysis: The Freight TSI decreased 2.1% in March from February due to seasonally-adjusted decreases in truck tonnage and pipeline despite growth in water, rail carloads, rail intermodal, and air freight. The large decline in truck freight volumes, possibly due to supply chain issues, outweighed gains in other modes. The March decrease took place against the background of growth in other indicators from February to March.

The Federal Reserve Board Industrial Production (IP) Index grew 1.4% in March reflecting increases of 2.7% in manufacturing and 5.3% in mining, while utilities decreased 11.4%. Housing starts were up 19.4%. Personal Income increased by 21.1% (the Bureau of Economic Analysis notes that Personal Income in March was impacted by the continued government response to COVID-19). The Institute for Supply Management Manufacturing (ISM) index was up 3.9 points to 64.7, indicating growing strength in manufacturing.

The fourth-quarter TSI decrease of 3.3% came in the context of continued quarterly GDP growth.

Although the March Passenger TSI is being withheld because of the difficulty of estimating airline passenger travel and other components, the February index is now being released. The index increased 9.2% from January to February following an increase of 9.3% in January. Air passenger, and rail passenger grew, while transit was down. The Passenger TSI remains above the levels of March 2020 through January 2021 though it has not returned to its level in February 2020, the last month before the impact of the pandemic. It remained below any level the Passenger TSI had been before the pandemic for the 12th consecutive month. 

Trend: The March decline was the second consecutive decline for a cumulative decline of 5.1% since January. It was the second largest monthly decrease since April 2020. The freight TSI is now below its level of July 2020. The index is 8.1% below its record level of 141.5 in August 2019 and has decreased in 11 of the last 19 months since that peak. For additional historical data, go to TSI data.

Index highs and lows: For-hire freight shipments in March 2021 (130.0) were 37.0% higher than the low in April 2009 during the recession (94.9). The March 2021 level was 8.1% below the historic peak reached in August 2019 (141.5).

Year-to-date: For-hire freight shipments measured by the index were down 3.3% in March compared to the end of 2020 (Table 3).

Long-term trend: For-hire freight shipments are up 7.8% in the five years from March 2016 and are up 17.0% in the 10 years from March 2011 (Table 5).  

Same month of previous year: March 2021 for-hire freight shipments were down 4.0% from March 2020 (Tables 4, 5). 

1st quarter changes: The freight TSI fell 3.3% in the 1st quarter following two consecutive quarterly increases (Table 6).  

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 April 2021 index is scheduled for June 9.

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.

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).