Generating an OD Table with Disaggregated Zone Structure for Land Development Program 12th TRB National Planning Application Conference Xiaobo Liu, Ph.D. Adam Lanigan John Pavlovich, P.E. Jacobs Engineering Group 299 Madison Ave Morristown, NJ 07962

Introduction The aggregated TAZ structure in regional planning models cannot provide adequate information for land development planning applications How to employ detailed trip generation to create an OD table in the land development area while maximizing flexibility and efficiency for planning analysis? The paper presents a simple, effective and efficient approach to investigate the traffic patterns with more accuracy

Determining TAZ Structure Maximizing disaggregation of the TAZ structure would provide the most detailed information for planning purposes and traffic operational analysis The disaggregated zones could be grouped into different sectors/blocks for trip generation to fit the land development programs This could improve the flexibility and efficiency of updating the different elements during the planning procedure, such as updating the type and intensity of land development, various access plans, and geometric layouts

Proposed Procedure Trip Generation - block based Converting Block to “Zone” Structure Disaggregated P/A Assignment Normalization Land Development Program - block based Setup Disaggregated “Zone” Structure I-I Distribution I-E /E-I Distribution Regional Demand Model Traffic Directional Distribution E-E Distribution O-D Table

RIVER BEND DEVELOPMENT PLAN

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios Formulate Multi-Phase Land Use Mix

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios Formulate Multi-Phase Land Use Mix Maximize Retail Component

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios Formulate Multi-Phase Land Use Mix Maximize Retail Component Minimize Parking Requirements

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios Formulate Multi-Phase Land Use Mix Maximize Retail Component Minimize Parking Fast Track analysis

RIVER BEND DEVELOPMENT PLAN Issues: Assess Multiple Development Scenarios Formulate Multi-Phase Land Use Mix Maximize Retail Component Minimize Parking Fast Track analysis Set Final Street Network

Conventional Approach Shortcomings: No O-D Table Lack of I-I trip generation that could be essential for urban area Analyzing alternatives requires manual adjustments and traffic assignment: time consuming, labor intensive, and error prone

Land Development Program Development area consists of 12 blocks (A-L) based on roadway boundaries Each block has different land use plan Land development program including the size of the development and land use, was changed frequently by developer to achieve max marketing Roadway access was also updated over several iterations to provide best access to the site 32 zones proposed in the study area, including 2 external zones and 30 internal zones.

Land Use Plan

Converting Trips from Block to “Zone” The concept of distributing the trips produced and attracted by each block may be a bit abstract. Here is a breakdown: Think of the Zones (TAZs) as driveways. They represent the loading points for the trips generated by each block. You are essentially controlling how the trips get distributed between the individual driveways for a block. (i.e. 75% leave from this driveway, 25% from the other.)

Trip Generation TRIP GENERATION To conduct the transportation analysis for land development in small area rather than regional analysis, ITE trip generation manual is applied for individual land uses.

Production/Attraction Assignment Obtain trip productions and attractions for the land development area from ITE Trip Generation Manual Breakdown block-based Productions/Attractions into zone-based First, we need to turn the generated trips into Production and Attraction trips. Break down the Block based trips into Traffic Analysis Zones (TAZs or just zones) so that the trips produced by and attracted to (exit and enter from the Trip Gen stage) each block can be distributed, in favor of transportation analysis requirement.

Internal-External External-Internal Distribution The proportion of the total trips generated from internal zones to external zones (and external to internal) could be determined from a regional demand model or local knowledge of the development area Include pass-by trips to the development zones in the O-D distribution specify how trips produced by and attracted to your TAZs relate to the External Zones in your model based on the relative proportion - obtained from regional planning model or field observation.

Internal-Internal Distribution Production trips are used as the base I-I trips are distributed using a gravity model based on the internal zone activity (multiply or add weight)

External-External Distribution Determine the distribution of external zone to external zone traffic from a regional demand model Credit the pass-by trips to the development zones credited from the E-E trips

Total Vehicle Trips EXAMPLE: TOTAL TRIPS 100 LESS TRANSIT ADJUSTMENT 15 NET TOTAL TRIPS 85 LESS INTERNAL/INTERNAL TRIPS 18 EXTERNAL/EXTERNAL PASS BY TRIPS 27 NET NEW VEHICLE TRIPS GENERATED 40

O-D Table and Applications

Results Phased Land Use Development Program by Block Sizing of Parking Facilities Fast-tracking of Street Infrastructure Ability to Evaluate Changes in Land Use Elements to Respond to Economic Conditions

Questions? Contact: John Pavlovich – john.pavlovich@jacobs.com Adam Lanigan – adam.lanigan@jacobs.com Xiaobo Liu – xiaobo.liu@jacobs.com