Transportation series provide some of the better indicators of economic activity. Their releases are not listed in most popular economic calendars for investors.
The London-based Baltic Exchange‘s Baltic Dry Index has received considerable attention in the past year. It is an index that tracks costs of bulk ocean shipping prices world-wide. It is widely considered a leading indicator and is updated daily.
The Bureau of Transportation Statistics provides numerous time series detailing aggregate transportation usage in the United States. Some of the more prominent are listed in their Key Transportation Indicators report. The BTS also compiles a variety of other transportation statistics.
The Association of American Railroads provides weekly summaries of railroad transportation data. The data tables are in PDF format.
more to come
It is clear that many transportation indicators have strong seasonal fluctuations, and the releases for many are not seasonally adjusted. One notable exception: the Transportation Services Index (TSI). Unfortunately, the TSI is subject to revisions as much as four months prior. It is still under active development. The BTS provides a nice overview of the TSI (which includes a tutorial on some common index weighting schemes and also some details on the TSI’s seasonal adjustment).