They also verify the accuracy of measurements and calculations done at survey sites. They compile notes, sketches and records of measurement data. Assistants hold vertical rods in place while technicians sight on them with special instruments, called theodolites, to establish distances and angles. Assistants may also clear away brush and trees from the lines of a survey, set up traffic warnings and flag vehicles. Survey teams also spend time in offices planning surveys, drawing maps, preparing reports and doing computations for completed site surveys.
Workers also stand for long periods.
They walk long distances with heavy packs of equipment. They are subject to all kinds of weather as well as sunburn, poison oak, snake and insect bites and other hazards. There is danger on construction projects from moving machinery, falling objects, and moving vehicles on highway work. The work requires the ability to communicate by hand and voice signals over great distances. Occasionally, workers must drive long distances to survey sites.