## 3 Literature Review
The most commonly used parameters for The RTA database are gross floor area available to visitors (GFA) and housing units [17]. In New Zealand, the New Zealand Trips Database Bureau--TDB--provides a travel-generating database containing 693 New Zealand locations and 192 Australian RTA locations. Travel rates can be calculated using various parameters or data fields. The most common rate is per 100 m\({}^{2}\) gross area--GFA [16]. The two established travel-generating manuals most commonly used in South Africa are the Committee of Transport Officers Handbook [18] and the National Ministry of Transport Handbook [19]. According to [PERSON] et al. [20], the travel rates used in the COTO manual are based on insufficient data, and in some cases international data that may not necessarily be applicable to South African traffic conditions. Therefore, there is a need to develop travel generation rates that are based on local data and comparable to international data in South Africa. The NdoT was originally adopted in 1989 and provides an estimate of the number of expected trips for a range of land uses. It was reproduced in 1995 and is now widely used. This document identifies the trip production rates for the various movements and factors affecting the trip production. In the doctoral dissertation [21], a comparison was made between the actual rates of generating trips for shopping centres in low-income settlements and the accepted rates of generating trips from the manual (NdoT and Coto). The conclusion is that the difference between the actual recorded travel rate for the three shopping centres in the low-income area and the Coto rate is less than 10%, which is considered an acceptable degree of accuracy when generating travel for new development is envisaged, while the NDoT rates are not considered appropriate for these developments, as they are significantly higher (up to 77%) than the actual recorded rates. The conclusion is that the trip generation standards used are not always compatible with the South African context and that the existing trip generation standards need to be updated. The Abu Dhabi Department of Transportation (DoT) has developed the Abu Dhabi Road and Transit Authority [22] for several land uses in the United Arab Emirates-based on best international practices and extensive research and surveys conducted through development trends in the Emirates (analyses and research from nearly 400 different locations across the Emirates). Trip generation rates are determined for each land use for three periods during the day (morning, noon and evening) to make the manual compatible with other international handbooks, and in general, the methodology is similar to the ITE methodology. In Brazil, a certain number of studies have been conducted to estimate the volume of travel generated by shopping centres. Articles [23; 24] were developed based on data collected in shopping centres in the city of Sao Paolo, while [PERSON] [25] and [PERSON] [26], in their articles, used the data obtained from the shopping centres mostly in big towns in different regions of the country. Apart from the above-mentioned studies, certain research studies for the assessment of the volume of travel generated by shopping centres in Brazil were conducted by other authors [27; 28; 29]. In all mentioned articles, when estimating the number of vehicles attracted by shopping centres, only the size of the building, i.e., the gross leasable area or the total built-up area, is taken into account  
In different individual surveys around the world, many travel generation studies have been carried out, focusing on specific types of land use. So, among other things, there are studies that have focused on shopping centres. The 1977 New Hampshire Department study was one of the first to focus on trips generated by [PERSON] and [PERSON] [30]. The study proposed two different models.