This synthesis will be of interest to administrators, operating personnel, and others interested in the management and operation of telecommunications systems in transportation agencies. Information is provided on the fundamentals of telecommunications, types of systems available, current uses in state DOTs, and implementation procedures and alternatives. Most departments of transportation have telephone and radio systems in use for communications with their own personnel and with the public. This report of the Transportation Research Board describes those systems as well as other telecommunications options that are in use by transportation agencies or are available for their use.  The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3392