The Government of Thailand has announced plans to undertake a USD2.33 billion highway project linking Saraburi and Nakhon Nayok and reduce congestion on the existing Phahon Yothin Road (Highway 1) in Bangkok. The proposed road project is currently awaiting approval from the Expressway Authority of Thailand (EXAT).

Contract to construct the Chalong Rat to Nakhon Ayeok-Sarabur Expressway is expected to be awarded in 2023, with construction work scheduled to commence in 2024. The highway will be constructed in four phases and is expected to open to traffic in 2026.