getting started 2

What information is required to support the analyses?
Three types of input data are required, including geometric characteristics, operating parameters, and traffic data. Some of the data items will be used to determine the facility class designation, while other items are required to carry out the LOS estimation procedures. At this point, we are interested only in identifying what we need to know. The assumptions and application of default values will be indicated here, but the assignment of site-specific values and their use in the HCM procedures will be addressed in connection with each of the problems in this case study.

To establish the data requirements, it is necessary to refer to each of the facility chapters to identify the important determinants of the level of service on a facility. Referring to Chapter 10 (Urban Street Concepts), we are able to learn that the information in Exhibit 3-4 is needed to determine the arterial class:

Exhibit 3-4. Information Required to Determine Arterial Class
Data Item	Source or Assumptions
Arterial function (principal or minor)	Krome Avenue has the characteristics of a principal arterial
Driveway access density (very low, low, moderate, high)	Very low throughout the entire length
Cross section characteristics (divided or undivided, shoulders or not)	Undivided, with shoulders
Signal density (signals per mile)	Measured distances will be used
Speed limit	Will be obtained from a field survey
Roadside development (low, medium, moderate, high)	Very Low development throughout the route
Pedestrian activity level	Negligible pedestrian activity
Is parking allowed?	No parking anywhere on the route
Are there exclusive left-turn lanes?	Yes, except at one intersection