Chapter 3: Local Road Planning 83 4.2. Level of Service for Local Roads 4.2.1 Local Road Traffic Volume Traffic or vehicle volume determines the over-all loading unto the pavement of a local road. It is therefore important to consider the present and future (projected) traffic volume passing unto a local road. An increase in future traffic volume will entail necessary design changes for a local road such as geometric configuration and pavement type. Such design changes should make the local road sufficient to carry the design traffic volume without a drop of level of service. Table 3.7 lists down the vehicle classification used in surveying the traffic volume of a local road. Each vehicle is counted as they pass through a section of a local road. Engineers will often use the number of vehicles passing a point or entering an intersection in the analysis of roadway operations. The two basic methods of collecting data are manual observation and automatic recording. Each has their use and effectiveness depending on the type of information needed for analysis. The traffic data is the basis of all analysis in a traffic impact study and careful consideration should be given to the locations, types of counts and duration of counts. This also the basis for the Geometric improvement of a certain road section and for its pavement design. Table 3.7 Vehicle Classification for Traffic Survey of a Local Road