Thailand’s Department of Rural Roads (DRR) maintains secondary and connector roads across the country. Compared to DOH, DRR projects are more numerous but smaller in scale per project. Understanding DRR’s TOR is essential for contractors working in provincial markets.
Standards used in DRR projects
DRR uses the same TIS standards as DOH, but typically in smaller sizes:
- TIS 128-2560 — Round RC pipes Ø 0.30 – 1.00 m (the most common size range)
- TIS 1164-2559 — Box culverts 0.50 × 0.50 to 1.00 × 1.00 m
- TIS 1165-2559 — Mid-size box culverts (less common in rural work)
Most common sizes in DRR projects: round pipes Ø 600 / Ø 800 mm and box culverts 0.60 × 0.60 / 0.80 × 0.80 m.
Key differences from DOH
DRR projects differ from DOH projects:
- Volume per project: typically 100-500 pieces
- Geographic spread: multiple delivery points within one province
- Documentation level: requires valid TIS, less extensive paperwork than DOH
- Project budgets: smaller, requiring competitive factory pricing
Common DRR sizes
| Type | Size | Application |
|---|---|---|
| RC pipe | Ø 400 mm | Small lane under-road drainage |
| RC pipe | Ø 600 mm | Main rural road drainage |
| Box culvert | 0.60 × 0.60 m | Small canal crossings |
| Box culvert | 1.00 × 1.00 m | Larger drainage points |
Tips for provincial contractors
- Choose a supplier that delivers to multiple points in your province (consolidates trips)
- Prefer suppliers with in-stock popular sizes (no lead-time waiting)
- Verify supplier’s TIS documentation is acceptable to your provincial DRR office
Request a quote
Siripong Cement has delivered DRR projects across Central Thailand for 30+ years — popular sizes in stock for 24-48 hour delivery, factory-direct pricing from Pathum Thani.
Contact us or LINE OA @siripongcement