California Urban Infill Trip Generation Study Jim Daisa, P.E.
What We Did in the Study Develop trip generation rates for land uses in urban areas of California Establish a California urban land use trip generation database Supplement Institute of Transportation Engineers (ITE) published rates
Why We Did the Study Data to support transportation planning for: Urban infill development Higher densities and broader range of housing types Mixed use and transitoriented development Environments where walking, bicycling and transit are attractive and viable forms of transportation
Why Not Use Current Data? ITE trip generation data: Reflects isolated suburban land uses Little or no transit service Little or no pedestrian and bike access Free and ample parking Low mix of uses Sites selected for ease of data collection Not applicable to urban cores
Defining Urban Infill Areas As defined by ITE Central Business District, Central City, Not Downtown Suburban Center Area As defined in Proposed Recommended Practice for Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities General Urban Urban Center Urban Core
Transit Criteria for Selecting Sites Within 1/3 mile of rail transit station for bus or rail transit service, or Intersection of two major bus routes, Within 300 feet of a bus rapid transit corridor. Maximum scheduled headways of 15 minutes for at least 5 hours per day
Few areas in the Bay Area met urban criteria Even fewer areas met the transit proximity criteria 7
How We Collected Data ITE methodology not appropriate in urban areas Traffic counts do not capture trips by. People who park in off-site facilities People who park on street People who park nearby and link trips with other uses Intercept surveys and statistical analysis Mode of travel Other travel characteristics Demographic information
Urban Office Sites
Urban Residential Sites
Urban Retail Sites
Residential Trip Rates Surveyed Rates ITE Average Rates Site Unit Size (DU's) Total AM Peak Trip Rate Total PM Peak Trip Rate Total AM Peak Trip Rate Total PM Peak Trip Rate Bachenheimer Building 44 0.00 0.04 0.30 0.39 Gaia Building 89 0.05 0.31 0.30 0.39 Acton Courtyard 71 0.22 0.17 0.30 0.39 Touriel Building 34 0.05 0.15 0.30 0.39 Berkeleyan Apartments 56 0.07 0.09 0.30 0.39 Fine Arts Building 100 0.13 0.13 0.30 0.39 Horizon Property 211 0.10 0.17 0.34 0.38 Atria 149 0.46 0.41 0.44 0.52 Average 94 0.14 0.18 0.32 0.41
Residential AM Rates 45 40 Comparison Between Surveyed Trip Results and ITE Standard Trip Estimates (ITE 223) - Mid Rise Apartments - AM peak Hour Surveyed AM Trips ITE Standard AM Trips 35 Average Vehicle Trips 30 25 20 15 10 5 0 0 20 40 60 80 100 120 Number of Dw elling Units
Residential PM Rates 45 40 Comparison Between Surveyed Trip Results and ITE Standard Trip Estimates (ITE 223) - Mid Rise Apartments - PM Peak Hour Surveyed PM Trips ITE Standard PM Trips 35 30 Average Vehicle Trips 25 20 15 10 5 0 0 20 40 60 80 100 120 Number of Dw elling Units
National Cooperative Highway Research Program NCHRP Report 758 Trip-Generation Rates for Transportation Impact Analyses of Infill Developments
Objective Develop an easily applied methodology for: Site-specific transportation impact analyses of infill development projects located within existing Define infill development for application of methodology Address different types of land use
Potential Methodologies Adjustments to ITE rates Table lookup Travel demand forecast model-based Empirical trip generation data Local trip or parking generation studies Unique methods (e.g., one-of-a-kind research) Synthesis of above
Identifying Urban Contexts Defining urban Where auto trip generation is measurably different than ITE Trip Generation Manual Is this suburban, general urban, urban center or urban core?? 18
Visualizing Context
Selected Method Adjustment to ITE trip generation rates Proxy method Household Travel Survey method
Approach to Proxy Method
Output from Household Travel Survey Method
Update on: Trip Generation Handbook 3 rd Edition Institute of Transportation Engineers
Person Trips General Approach for Estimating Multimodal Site Person Trips Conversion between Vehicle Trips and Person Trips Study Site and Baseline Mode Shares and Vehicle Occupancy
Trip Generation For Mixed-use Mixed-Use Development Classified as a Single Land Use Underlying Assumptions about Internal Capture Estimating Mixed-Use Trip Generation Data Collection Development
Trip Generation For Urban Infill / Redevelopment Definition of Infill development Underlying Assumptions for Infill Site Trip Generation Process for Estimating Infill Trip Generation Examples of Recommended Process
Trip Generation For A Transitfriendly Development Definition of Transit-Friendly Development Factors Affecting Transit Use at a TFD Process for Estimating Transit Trips at a TFD Site
Other Content Use of local data Primary, pass-by, and diverted trips Truck trip generation Data collection procedures Synopses of key research Transportation Demand Management Use of data for travel demand models Overview of travel survey types