Trucks are available with optional equipment that may be useful in some areas. In some remote areas, vehicles are equipped with two-way radios. The various kinds of optional equipment have various disadvantages and limitations such as increased initial cost, increased operating and maintenance cost, increased downtime for the truck, difficulty in obtaining replacement parts, a decrease in the truck's handling qualities, and a decrease in road speed. In areas with good roads and little off-road travel is required, passenger vehicles are adequate. Passenger vehicles also are used to transport groups for field reviews.
Specialized vehicles are necessary in some areas.
Marsh buggies with large buoyant tires and airboats are used in swamps and marshes. Snowmobiles provide access in winter to some northern swamps where travel is impossible or impractical in other seasons. Trail bikes or ATVs can be used in areas that could otherwise be reached only by walking. Specialized vehicles must be reliable in relatively inaccessible areas. The equipment must be transported to the use area.