BTS’ National Transportation Statistics Updated. The U.S. Department of Transportation’s Bureau of Transportation Statistics (BTS) today updated National Transportation Statistics (NTS) – a web-only reference guide to national-level transportation data. NTS, updated quarterly, includes a wide range of national transportation information. NTS consists of more than 260 tables of national data on the transportation system, safety, the economy and energy and the environment, of which 66 were updated today. The next quarterly update is scheduled for July. NTS can be viewed on the BTS website. Contact: Dave Smallen (202) 366-5568.