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105 With the increase in emphasis on livability, compact cities, Create a land use classification structure that would permit and smart growth in general, MXDs have become more pop- disaggregation of the six land uses to more detailed cate- ular. Many are found in midtown-type urban areas (i.e., the gories should enough data become available; central portion of a city or urban area that is outside the CBD Include the effects of proximity (i.e., convenient walking but has higher densities than suburban or general urban and distance) among interacting land uses to represent both may include an outlying business district). Others are found compactness and design; and in suburban locations and a few in urban peripheries. The Provide a method that could easily be put in spreadsheet research team did not include downtowns because they would form. be very difficult to survey and do not develop as one project or development and, therefore, would not need a TIA for the This method was tested for its ability to estimate external downtown. vehicle trip generation. The existing ITE method estimates During the period this project was active, the research team produce about one-half of the estimation error that raw ITE received dozens of calls asking for internal capture data for trip generation rates produce. The method developed in this land uses and time periods not included in the ITE method. project cuts the estimation error in half again, or roughly to Requests were most frequently received for about one-fourth of the raw trip generation rates. The recommended method is described in Chapter 3. The A.M. peak-hour internal capture rates; researchers recommend its use for developments of up to Land uses not included in the ITE method--most notably 300 acres. Additional data and/or further testing could vali- hotels, cinemas, and restaurants; and date its use for larger developments, but that has not yet been Very large MXDs in outlying areas. attempted. The researchers do not recommend use of this method for downtowns, SACs, or new town types of devel- Available Data opment; the researchers do not believe it will be applicable. There are very limited data available that are capable of sup- The method produced has a component that estimates porting internal capture rate estimation methodology that can the effects of proximity. Unfortunately, the database is small use information that is available at the time of zoning. Three enough for the P.M. period that factors could only be devel- Florida surveys plus three pilot studies conducted for this oped for some land use pairs. Absence of A.M. peak-hour data project were the only surveys with enough detail to develop from the Florida studies precluded any A.M. proximity factors internal capture methodology from being developed. This project's estimation method gen- erally produced slightly closer P.M. estimates with the prox- For both A.M. and P.M. peak hours; imity factor included. It is recommended for use, but it is also For use with information that is available at the time of recommended that when additional data becomes available, zoning requests and can be reliably projected; attempts should be made to develop proximity factors for more That provides the ability to analyze the effect of proximity land use pairs. of land uses to each other; and That is sensitive to differences in land use mix. Suggested Modifications to Existing ITE Procedures Some cordon counts have been completed for various peri- ods and could be used for validation testing, but, by themselves As mentioned previously, the recommended estimation with land use information, they do not provide what is needed method builds on the current ITE internal trip capture proce- to develop a sensitive procedure. More data are needed. dures contained in the second edition of the Trip Generation Handbook (1). Incorporation of this project's recommenda- Internal Capture tions could be accomplished by performing the following: Estimation Methodology Expanding Tables 7.1 and 7.2 of the Trip Generation Hand- Expanded ITE Methodology book (1) to include all six land uses covered in this report; and This project expanded the database from three to six devel- Adding the proximity adjustment to be made after the opments and, after considering options, expanded the ITE unconstrained internal capture estimates are performed method to but before the balancing process. Add the weekday A.M. peak hour; The data collection procedures could be modified to include Add restaurant, cinema, and hotel land uses; those recommended in this project, including the next section.