This could be the hottest summer ever — for freight Inbound TEU bookings are set to exceed 2020 peak by nearly 8% this week 0 6 3 minutes read Chart of the Week: Inbound Ocean TEU Volume Index , Van Outbound Tender Volume Index – USA SONAR:IOTI.USA, VOTVI.USA The Inbound Ocean TEU Volume Index (IOTI), which measures maritime bookings for twenty-foot equivalent units for U.S. imports, is set to hit an all-time high this week. The IOTI starts in January 2019 but covers one of the most active periods in maritime shipping thanks to the pandemic. With imports being tied more closely than ever to surface freight volumes and transportation demand, this could be a signal of an extremely active summer for domestic surface transportation providers.