【正文】 those produced by queuing can be identified as those preceding another result at approximate same time.EXTIM identified 150 records that marked the start and stop of the load activities. Further review and reduction by the user of the identified records resulted in 84 key records. This level of reduction from 18,850 to 84 records is very similar to that of the ADTIM and represents a greater than % reduction.FBTIM was used to identify the records key to the haul and return activities. The duration of the haul and return activities can be characterized as the time required for the truck to travel through or between FBTIM areas. For purposes of illustration, the FBTIM areas will be applied in both manners and are presented in Fig. 6. The truck traveled through boundary number 1 during thefirst operation and between boundaries 2 and 3 during the second operation.Further manual reduction of the data resulting from the TIMs may be necessary to produce a set of critical records. Overlapping areas can be defined for the FBTIM and produce results that are both accurate and useful. It is important to understand that the results produced may also overlap, and the appropriate overlapping results should be neglected.Data reduction by FBTIM reduced the number of records from 18,850 to 202. Further review and reduction by the user resulted in the identification of 164 key records that mark the start and stop of activities. These 164 records represent less than 1% of the total number of data records collected。and previous record must be outside the area for arrival times, or the next record must be outside the area for departure times.The ADTIM evaluates each of the three criteria in the order in which they were presented. To ensure that the recorded velocity was zero, all calculations are performed on a v=0 worksheet that contains only those records where velocity equaled zero.The user defines the area within which the truck was stopped by providing a set of central coordinates and a radial distance on the ADTIM input form, shown in Fig. 4. The user may define as many as five ADTIM areas.The third criterion is evaluated within the software. For each defined area, each position recorded with zero velocity is used to calculate a distance between the truck and the defined point. This calculated distance is pared to the usersupplied critical distance to determine if the truck is within the defined area, and each record is marked appropriately. The records are then checked again to identify changes in truck status, and those records corresponding to arrive and depart times are marked with the time at which the position was recorded.External Data Time Identification Module Some earthmoving activities do not always occur in the same location, but rather occur relative to a second location that moves over time, for example, a truck loaded by a rubbertired the location of the loading activity may not move significantly from one instance to the next, it may change significantly over the course of a day or several days. The area in which the load activity occurs thus moves depending on the location of the loader. The External Data TIM (EXTIM) was developed to return the first (arrive) and last (depart) times at which the truck stops within a given distance of a moving point defined by the loader position, or any other instrumented equipment.The EXTIM operates very similarly to the ADTIM except that central coordinates of the area are defined by the positions collected for the moving point. The coordinates are those recorded by the system installed on another piece of equipment, such as a rubbertired loader. Therefore, prior to executing EXTIM, it is necessary to have executed the Import Text routine on the data file collected from the loader system. When the EXTIM button is selected from the user interface, the EXTIM input dialog box,similar to that of the ADTIM, appears and prompts the user for the reference data file to be read and the associated critical distance.The EXTIM calculates the distance between the truck andloader for each position recorded and pares this calculated distance to the critical distance. Because the parison is made between the position recorded on the truck and that recorded on the loader, it is necessary to time match the records. EXTIM loops through each recorded truck time and pares it to the loader time in the same row, eliminating the earlier record if a match is not found, and then repeating until a match is plete time match is ensured by looping through all of the truck data, not just providing an initial time match. The enter andexit times are identified and summarized in a manner similar to the ADTIM.Fixed Boundary Time Identification ModuleNot all earthmoving activities are associated with the truck stopped in a certain area, but rather can be associated with thetruck traveling in or through certain areas. The haul and return activities or travel times for roadway segments are examples of truck activities for which the truck is moving. The Fixed Boundary TIM ?FBTIM? was developed to identify the times at which a truck crosses userdefined boundaries, thus entering or exiting the defined area. Establishing proper boundaries will allow the user to calculate transit or travel times.Two criteria need to be satisfied for a record to be considered an enter or exit time by the FBTIM: of the truck is within the defined boundaries。and required to travel through or between fixed areas—.,a haul truck traveling between load and dump areas. Time identification modules (TIMs) were developed to identify the GPS data records corresponding to the beginning and end of activities associated with each of the three specific modules have been developed in the VBA language for execution in Excel. The results produced by TIMs have been pared to those produced by a PAVIC+ analysis of the videotaped operation in an effort to validate the TIMs results.