AADT-- Annual average daily traffic determined by dividing a count of the total yearly traffic volume by 365. Units are vehicles per day.
ADT-- Average daily traffic that results from dividing a traffic count obtained during a given time period by the number of days in that time period.
Cadastral Survey-- A survey that identifies the legal boundaries between public and private lands.
Design Speed-- The maximum safe speed that can be maintained when conditions permit the design features of the highway to govern.
D-- Directional distribution. The percentage of the two-way traffic volume traveling in the direction of interest, expressed as a decimal.
DHV-- Design hour volume. The two-way traffic volume that is determined by multiplying the ADT by a percentage factor called the K-factor (see below).
DDHV-- Directional design hour volume expressed as vehicles per hour.
Functional Class-- The classification of roadways by operational status such as freeway, arterial, collectors and local.
K-factor-- The proportion of daily traffic occurring during the peak hour, expressed as a decimal. For design purposes, K represents the proportion of AADT occurring during the thirtieth highest peak hour of the year.
Located Centerline Survey-- A survey of the centerline of a planned or existing highway.
Planimetric Map-- Illustrates features such as roads, buildings, water, fences, vegetation, bridges, railroads.
Stations-- Points along a line (usually a survey line) of equal distance designated either in feet or meters. Points at multiples of 100 meters or feet are typically called full stations.
Topographic Map-- Illustrates elevation with the use of contour lines and spot elevations.
Topographic Survey-- A survey that establishes the configuration of the ground and the location of natural and man-made objects.