Current trip generation models an statistics, especially the ITE Trip Generation Manual, are based on single uses in vehicle-oriented suburban environments, with a heavy bias towards California and sunbelt states, although that may change with the 9th Edition. The following is some links that I've collected in doing research on trip generation for NU/TND development.
Traditional Neighborhood Development Trip Generation Study
Asad J. Khattak, John Stone, William E. Letchworth
Carolina Transportation Program, North Carolina State University
From the executive summary:
In terms of traveler behavior this study finds no statistically significant difference between the total trips made by households in the Southern Village TND and the comparable conventional developments. However, TND households substituted driving trips with alternative modes, i.e., the automobile trip generation rate for the TND was significantly lower (by 1.25 trips per day per household) than conventional neighborhoods. In addition, empirical evidence suggests that TND
• Lower vehicle miles traveled—on average, the TND single-family households travel 18 miles less per day.
• Higher share of alternative modes—in the TND, 78.4 percent of the trips were by personal vehicle compared with 89.9 percent in the conventional neighborhoods.
• Lower external trips—on average, the TND households made 1.53 fewer external trips per day.
Travel behavior in neo-traditional neighborhood developments: A case study in USA
Asad J. Khattak, Daniel Rodriguez
Carolina Transportation Program
Traditional Development Trip Generation Characteristics
FLITE: Florida Institute of Transportation Engineers
On Form Versus Function: Will The New Urbanism Reduce Traffic or Increase It?
University of California Transportation Center
Land Use Impacts on Transport: How Land Use Patterns Affect Travel Behavior
TDM Encyclopedia - Victoria Transport Policy Institute
Vehicle Trip Reduction Impacts of Transit-Oriented Housing
Robert Cervero, University of California, Berkeley; G. B. Arrington, PB Placemaking
Evidence on Mixed-Use Trip Generation - Local Validation of the National Survey
Mark Feldman, Reid Ewing, Jerry Walters
If you come across any more studies or guides, feel free to post a reply with links.