Geography
Hanoi first, then the corridor you name
Most weeks begin on Ma May Street. Field days follow the compounds you can open, from inner-district roofs to rest stops on the highway out of the city.
Inner Hanoi
Hoan Kiem, Ba Dinh, Hai Ba Trung, and Tay Ho are a motorbike morning from the office. Cabinet walks and rooftop photographs fit a single field week when landlord letters are ready.
Red River Delta
Hung Yen, Bac Ninh, and the ring-road laterals need a contracted surveyor and an extra night. Fibre feeder sketches along canals are booked after we see as-builts or hear that they are missing.
Further travel
Ho Chi Minh City ring roads and Mekong towns appear in the fee letter as extra field days. High water can add a week; we write that into the calendar before anyone flies.
If your boundary sits in these areas, choose a study type or send the province name.