Richard Turnock, chief technology officer of Kapsch TrafficCom North America explains what advantages its newly-opened TDM protocol can offer as a US-wide standard for tolling interoperability. The electronic tolling industry across the United States is evolving. Historically it was characterised by clusters of interoperability where a motorist may be able to use the same transponder across a large area, such as the 15-State E-ZPass system, or be confined to a single State system. Now, however, the industry