ch activities close to each other and to residences, so that the shorter trip changes from what should have been an external trip by motor vehicle, to an internal walk, bike, or transit trip (Feldman, Ewing & Walters, 2010).
Because the mixed use configuration is essentially internal and encourages pedestrian and non-automobile transportation methods, the forecasting of traffic patterns through trip generation and traffic projection utilised by practitioners tended to be similar to each other. The Institute of Transportation Engineers (ITE) have formulated a method by which trip generation can be performed. Feldman, Ewing and Walters (2010) describe the procedure in the following steps:
The estimated figures are then multiplied by a set of per-unit trip generation rates that ITE has developed, to get a preliminary estimate of the number of vehicle trips that are generated by the site;
The initial estimates of generated trips are then lowered by a certain percentage, based on lookup tables by the ITE. The reduction represents the internal capture of trips in the mixed use development. The share of internal trips as shown in the look-up table is multiplied by the total number of trips for each of the different uses, to arrive at a first estimate of internal trips for each use.
For each pair of uses (production and attraction, or source and destination use) are reconciled, so that the number of internal trips produced by one use is equal to the number of trips attracted by the other use. The lower of the two estimates of internal trips is the limitation of the number of internal trips created by the other use (Feldman, Ewing & Walters, 2010).
The traditional trip generation method developed by the ITE has some advantages when applied to mixed-use development areas. First, the process appears to be objective, because if two different analysts worked on the same data, they will arrive at the same result. The steps used for calculation are specific and do not