20 Baht - Rama IX Department of Highways

Issued to mark the 60th anniversary of the Thai Department of Highways, founded in 1952 under the Public Works Ministry to consolidate road construction authority that had previously been fragmented across regional administrations. Infrastructure development was a central pillar of Bhumibol Adulyadej's development programs, particularly in the rural north and northeast where unpaved tracks connected highland villages to lowland markets.

Commemorative 20 baht pieces of this type saw limited circulation outside official channels — most absorbed immediately by collectors and government gift sets.