Food & Drink is Unique ID 368 in the IAB Audience Taxonomy 1.1, in the Interest branch under Interest. Trillboards emits it on the bid request as a segtax=4 segment, the code every IAB-compliant DSP already reads, so a buyer already running "Food & Drink" elsewhere can point that strategy at DOOH screens without rewriting taxonomy. Over the most recent 30-day window the network logged 626 cohort observations tagged with this segment across 26,825 approved screens.
Trillboards inventory concentrates in Taxi Rideshare Tv, Convenience Store, Grocery. Taxi Rideshare Tv is the largest category at 12,548 approved screens, average floor $2.55 CPM. Those are network-wide venue counts; add a venue filter to the line item to hold delivery to the surfaces you want.
Buying one or two tiers up captures more of the network and less of the segment; buying this leaf does the reverse. The OpenRTB payload carries every level of the chain, so a single bid request can be targeted at Food & Drink or at any node above it. Interest cohorts land hardest when the venue reinforces the interest, so pair the segment with a venue filter.