The level of for-hire freight shipments in July measured by the Freight TSI (134.5) was 5.2% below the all-time high level of 141.9 in August 2019 (Table 2A). BTS’ TSI records begin in 2000. See historical TSI data.

The May index was revised from 136.7 to 136.9 in last month’s release. April was revised down slightly.

BTS is withholding the scheduled release of the passenger and combined indexes for July. The passenger index for July is a statistical estimate of airline passenger travel and other components based on historical trends up to June 2021. The statistical estimate does not fully account for the rapidly changing impacts of the coronavirus on the historical trend. Air freight for July 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 June 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 seasons from month-to-month comparisons.

Analysis: The Freight TSI decreased 1.6% in July from June due to seasonally-adjusted decreases in rail carloads, rail intermodal, trucking, water and pipeline. The only mode that grew in July was air freight. The July decrease took place against a background of mixed results for other indicators.

The Federal Reserve Board Industrial Production (IP) Index grew 0.9% in July, reflecting increases of 1.4% in manufacturing and 1.2% in mining while utilities shrank by 2.1%. Housing starts were down 7.0% Personal Income increased by 1.1%. The Institute for Supply Management Manufacturing (ISM) index was down 1.1 points to 59.5, indicating continued but slowing  growth in manufacturing.

Although the July Passenger TSI is being withheld because of the previously cited difficulty of estimating airline passenger travel and other components, the June index is now being released. The index increased 9.5% from May to June following an increase of 13.3% in April. Air passenger, rail passenger and transit all grew. The Passenger TSI has now exceeded its level of March 2020, the last month before the full impact of the pandemic, though it has not returned to its level in February 2020. It remained below any level the Passenger TSI had been before the pandemic for the 16th consecutive month. 

Trend: The July freight index decrease was the third consecutive decrease for a decrease of 2.3% since April. This was the fourth decrease in six months. The Freight TSI is at its second lowest level since November 2020 but is 7.3% above the pandemic low in April 2020. The index is 5.2% below its record level of 141.9 in August 2019 and has decreased in twelve of the last 23 months since that peak. For additional historical data, go to TSI data.

Index highs and lows: For-hire freight shipments in July 2021 (134.5) were 41.7% higher than the low in April 2009 during the recession (94.9). The July 2021 level was 5.2% below the historic peak reached in August 2019 (141.9) (Table 1A).

Year to date: For-hire freight shipments measured by the index were down 0.3% in July compared to the end of 2020 (Table 3).

Long-term trend: For-hire freight shipments are up 7% in the years from July 2016 and are up 21.8% in the 10 years from July 2011 (Table 5). 

Same month of previous year: July 2021 for-hire freight shipments were up 0.5% from July 2020 (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 August 2021 index is scheduled for October 14, 2021.

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 1: Freight Transportation Services Index since January 2021
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, 2009-2021

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

Table 2: Freight Transportation Services Index Monthly Changes, 2018-2021
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, 2018-2021

 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, 2012-2021
Percent change to July 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 July 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 2021 (July to July)

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).