The road distance is approximately 850-900 km. This journey involves complex international border crossings through Cambodia (Thailand-Cambodia and Cambodia-Vietnam borders), requiring specific vehicle import permits, international driving licenses, and potentially multiple visas. Car rental companies often have restrictions on cross-border travel with their vehicles. Fuel costs are an estimate and do not include tolls, which are likely to be incurred in all three countries. This option is generally considered challenging and not recommended for typical tourist travel.