Trip Generation for Smart Growthmedia2.planning.org/APA2012/Presentations/S483_Getting Trip...

Trip Generation for

Smart Growth

Christine Eary, SANDAG April 15, 2012

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San Diego Jurisdictions

Oceanside

Carlsbad

Encinitas

Solana Beach Del Mar

San Diego

Coronado

Imperial Beach

Chula Vista

National City

Lemon Grove

La Mesa El Cajon

Santee

Poway

Escondido San

Marcos

Vista

County of San Diego

San Diego

Riverside County

Imperial County

MEXICO

PACIFIC OCEAN

Orange County

3

San Diego Regional Comprehensive Plan

Urban Form

Transportation

Housing

Healthy Environment

Economic Prosperity

Public Facilities

Borders

Adopted by SANDAG in 2004

4

Smart Growth Tool Box

Planning Tools

• Smart Growth Concept Map

• I-PLACE3S Sketch Model

• Visualization Tools and

Smart Growth Photo Library

• Smart Growth Design Guidelines

• Trip Generation/Parking Study

• San Diego Regional Bicycle Plan

• Public Outreach Program

Financing Tools

• TransNet Smart Growth

Incentive Program

• TransNet Environmental

Mitigation Program

• TransNet Active

Transportation Grant

Program

5

Smart Growth

Concept Map

Study Purpose

• Supplement existing

published rates

• Provide data for smart

growth development

and planning in San

Diego region

Site Selection – TOD/MXD

• Visited 30+ sites

• Sites were initially selected based on input from SANDAG staff, member agencies, and Project Team

• 6 sites chosen

Site #1 - Rio Vista Trolley Station

Promenade

San Diego

Rio Vista Promenade, San Diego 9

Site #2 – La Mesa Village Plaza

La Mesa

La Mesa Village Plaza, La Mesa 11

Site #3 - Uptown District

San Diego

Uptown District, San Diego 13

Site #4 – The Village @ Morena Vista

San Diego

The Village at Morena Vista, San Diego 15

Site #5 - Hazard Center

San Diego

Hazard Center, San Diego 17

Site #6 – Otay Ranch

Chula Vista

Otay Ranch Heritage Town Center, Chula Vista 19

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Smart Growth

Concept Map

Site Selection – SANDAG SGOAs

(Smart Growth Opportunity Areas)

• List of 57 SGOAs chosen

• Counts not possible (too big)

• 20 of those had at least 100 trip records in household survey

• Comparison of trip reduction percentages between these sites and MXD model

MXD Model Validation – SGOAs

Figure 1

Net Vehicle Trip Reduction - Sites with >100 Survey

Records

0%

10%

20%

30%

40%

50%

60%

70%

80%

0% 20% 40% 60% 80%

Estimated

Ob

serv

ed

MXD method tends

to be conservative,

more likely to

underestimate

internalization

Study Adoption

• Change is scary, change is hard.

• Parking confused things

• Now incorporated into traffic impact study

data requests at SANDAG

• Traffic impact study guidelines next

Study URL

http://www.sandag.org/tripgeneration

Questions?

- Christine Eary, SANDAG

christine.eary@sandag.org

- Jerry Walters, Fehr & Peers

j.walters@fehrandpeers.com

- Richard Lee, Fehr & Peers

r.lee@fehrandpeers.com

Capturing the Transportation

Benefits of Mixed Use Development

APA National Planning Conference

April 2012

Jerry Walters ◊ Fehr & Peers

1. Density dwellings, jobs per acre

2. Diversity mix of housing, jobs, retail

3. Design connectivity, walkability

4. Destinations regional accessibility

5. Distance to Transit rail proximity

6. Development Scale pop, jobs

7. Demographics household size, income

8. Demand Management pricing …

“D” Factors that Reduce Trips and VMT

1D

Typical 4-Step Model “Blind Spots”

Reality Model’s View

Circulation Network

Walking Environment

Density, Clustering

7D Analysis of Travel Survey Data

• Statistical relationships from travel data for sites meeting ITE multi-use definition

• Assess influence of 7D’s, mix and scale

• Validate through comparison to field data

239 MXD: Seattle, Portland, Sacramento, Boston, Atlanta, Houston Validation: Northern and So. Cal, Texas, Georgia, Florida, Utah

Gateway Oaks, Sacramento River Place, Portland

Nationwide Survey of Mixed-Use Travel

• Density of population and employment

• Diversity: jobs/housing relative to regional balance • Diversity: balance of commercial, office, and public

• Design: intersections per square mile

• Destination Accessibility: jobs within 1 mile • Destination Accessibility: jobs within a 30 min by transit

• Distance to Transit: rail station, bus stops within ¼ mile

• Development Scale: MXD population and employment

• Demographics: household size, vehicle ownership

* Internal travel and walking, transit use, trip length

7D Factors Correlated with Reduced Travel

28 Nationwide Validation Sites

• 7 Florida sites (including ITE Trip Generation Handbook)

• 15 California sites

• 2 sites in Texas •

• 2 in Georgia, S Carolina

• 2 sites in Utah

• Variety of scale, mix, design

Atlantic Station, Atlanta Uptown District, San Diego

Irvine California Plano Texas

Mixed-Use Centers, California and Florida

Celebration Florida Otay Ranch California

South Davis, CA

South Davis, California

Moraga, CA

Mockingbird Station, Dallas Bay Street, Emeryville, CA

MXD Model Validation

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Exte

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rip

s (1

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Gross Trips Net Trips MXD Model Observed

Comparison of MXD Model to Other Methods (28 Validation Sites)

MXD Model Compared with ITE

Daily Predicted vs. Observed MXD External Vehicle Trips

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ITE MXD

MXD Acceptance

From Analytics to Tools

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S… S… S… S… S… S… S… S… S… S… S… S… S… S…

MXD BMP DRM ASAP

Capturing the Transportation

Benefits of Mixed Use Development

APA National Planning Conference

April 2012

Jerry Walters ◊ Fehr & Peers

ET+

Metropolitan Research Center – University of Utah

Fregonese Associates

Envision Utah

Salt Lake County

Wasatch Front Regional Council

Apps (requiring travel inputs in green)

Predictive Growth Model

Building and Land Use Types

Building Energy Consumption

7D Transportation Impacts

Return of Investment

H + T Costs

Air Quality and Climate Impacts

Fiscal Impact

Public Health

Employment Growth

Employment Resilience

Development Capital

Redevelopment Timing

Water Consumption

Transportation Safety

Workforce Housing

LEED-ND Application

Public Assets

Apps (requiring travel inputs in green)

7D App

Through pioneering research, University of Utah faculty have

modeled the effects of density (built space per acre), diversity

(land-use mix), distance to transit, destination accessibility, land-

use connectivity through design, development scale, and

demographics – the 7Ds, on internal capture of trips within mixed-

use developments (MXDs); external trips by walking, transit, and

private vehicle; and vehicle miles traveled (VMT).

ET+ will be expanded to include all trips and will develop interactive

coefficients to calculate internal capture, walk, transit, and private

vehicle trips, and VMT for comparison to current conditions and

future scenarios advancing 7D interactions.

7D Analysis - Innovations

• Pooled household travel data for MXDs in six

diverse regions

• Identified 239 MXDs through a bottom-up survey

process

• Included internal capture, mode choice for

external trips, and trip length as travel

outcome measures

Additional Innovations

• Estimated large number of 7D variables

consistently across regions

• Modeled travel relationships hierarchically

• Validated results through comparison to traffic

generation counts at an independent set of

mixed use sites in various parts of the U.S.

Six Diverse Regions

• Atlanta

• Boston

• Houston

• Portland

• Sacramento

• Seattle

Provide XY coordinates for trip ends, so we could zero in on individual sites when studying travel patterns to, from, and within MXDs

Provide individual parcel data, so we could study land-use mix down to the parcel level

Regions Based on Data Availability

Top-Down GIS-Based Approach

vs.

Bottom-Up Expert-Based Approach

Identifying MXDs

…A mixed-use development or district

consists of two or more land uses between

which trips can be made using local streets,

without having to use major streets. The

uses may include residential, retail, office,

and/or entertainment. There may be walk

trips between the uses.

New MXD Definition

Internal capture = 36%

Walking – 14%

Transit – 9%

Auto Trips – 7.7 miles

Example – RiverPlace (Portland)

239 MXDs

Metro

Survey

Year

MXDs

Mean Acreage

per MXD

Total Trip

Ends

Mean Trip

Ends per

MXD

Atlanta 2001 24 287 6,167 257

Boston 1991 59 175 3,578 61

Houston 1995 34 401 1,584 47

Portland 1994 53 116 6,146 116

Sacramento 2000 25 179 2,487 99

Seattle 1999 44 207 15,915 362

Total 239 211 35,877 150

Multiple Outcome Measures

INTERNAL – Dummy variable indicating that the trip remained within the development

WALK – Dummy variable indicating that the travel mode on a trip is walking (1=walk mode, 0=other)

TRANSIT - Dummy variable indicating that the travel mode on a trip is public bus or rail (1=transit, 0=other)

TDIST - Network trip distance between origin and destination locations for an external private vehicle trip, in miles

7D variables consistently defined

Density

Diversity

Design

Destination Accessibility

Distance to Transit

Development Scale

Demographics

Individual Level Variables

HHSIZE – Number of members of the

household

VEHCAP – Number of motorized vehicles

per person in the household

BUSSTOP – Dummy variable indicating that

the household lives within ¼ mile of a

bus stop (1=yes, 0=no)

ACTDEN – Population + employment density per square mile

JOBPOP – Balance of jobs to population within the MXD

LANDMIX – Entropy index that captures the variety of land uses based on acreage

INTDEN - Number of intersections within the MXD per square mile of gross area

EMPMILE – Total employment within one mile of the traffic analysis zones intersecting the MXD

EMP30T – Total employment within 30 minutes by transit of traffic analysis zones intersecting the MXD

STOPDEN – Number of bus stops within the MXD per square mile of gross area

RAIL – Rail station located within the MXD (1 = yes, 0=no)

MXD Level Variables

Region Level Variables

REGPOP – Population within the region

REGEMP – Employment within the region

REGACT – Activity within the region

(population + employment)

SPRAWL – Measure of overall regional

sprawl from same source

Hierarchical Modeling

Level 1 Trips/Individuals/Households

Level 2 MXDs

Level 3 Regions

Log odds of internal capture

(log-log form)

Home-Based Work Home-Based Other Non-Home Based

Coeff t-ratio p-value Coeff t-ratio p-value Coeff t-ratio p-value

constant -1.75 -2.43 -5.72

EMP 0.208 3.28 0.002

AREA 0.486 3.61 0.001 0.468 4.58 <0.001

JOBPOP 0.389 2.62 0.010 0.399 4.55 <0.001

INTDEN 0.385 1.92 0.055 0.638 4.95 <0.001

HHSIZE -1.33 -6.03 <0.001 -0.867 -13.0 <0.001 -0.237 -4.54 <0.001

VEHCAP -0.990 -4.15 <0.001 -0.590 -8.19 <0.001 -0.163 -3.00 0.003

pseudo-R2 0.01 0.20 0.30

Log odds of walking on external

trips (log-log form)

Home-Based Work Home-Based Other Non-Home Based

Coeff t-ratio p-value Coeff t-ratio p-value Coeff t-ratio p-value

constant -5.55 -10.96 -15.09

AREA -0.415 -4.27 <0.001

ACTDEN 0.370 2.74 0.007 0.377 3.12 0.003

JOBPOP 0.226 2.46 0.015 0.219 3.83 <0.001

INTDEN 0.803 5.05 <0.001

EMPMILE 0.385 3.12 0.002 0.450 5.05 <0.001 0.440 5.09 <0.001

HHSIZE -1.57 -6.29 <0.001 -0.486 -5.05 <0.001 -0.281 -2.59 0.010

VEHCAP -1.84 -7.00 <0.001 -0.768 -7.62 <0.001 -0.242 -2.13 0.033

pseudo-R2 0.19 0.51 0.64

Log odds of using transit on external

trips (log-log form)

Home-Based Work Home-Based Other Non-Home Based

Coeff t-ratio p-value Coeff t-ratio p-value Coeff t-ratio p-value

constant -4.32 -6.08 -2.69

ACTDEN 0.324 2.89 0.005

INTDEN 1.12 4.44 <0.001

EMP30T 0.209 2.98 0.004 0.134 3.29 0.002

HHSIZE -1.14 -6.31 <0.001 -0.958 -8.48 <0.001

VEHCAP -1.68 -8.56 <0.001 -1.09 -8.24 <0.001 -0.340 -3.74 <0.001

BUSSTOP 0.357 2.08 0.037 0.467 4.04 <0.001

pseudo-R2 0.47 NA NA

Distance of external automobile trips

(semi-log form)

Home-Based Work Home-Based Other Non-Home Based

Coeff t-ratio p-value Coeff t-ratio p-value Coeff t-ratio p-value

constant 6.54 4.33 8.99

AREA 1.07 2.92 0.004

JOBPOP -0.298 -1.88 0.061 -0.356 -2.38 0.018 -0.282 -2.05 0.041

INTDEN -0.832 -2.06 0.041

EMP20A -0.697 -4.79 <0.001 -0.823 -5.69 <0.001

EMP30A -1.19 -6.05 <0.001

HHSIZE 2.76 8.08 <0.001 0.772 5.06 <0.001 0.520 2.58 0.010

VEHCAP 2.76 7.26 <0.001 1.48 9.22 <0.001 1.06 5.12 <0.001

pseudo-R2 0.11 0.03 0.05

Primary Determinants of

Reduction in External Auto Trips

• The total and the relative amounts of population and

employment on the site

• The site size and activity density

• The amount of employment within walking distance of the site

• The pedestrian-friendliness of the site (small block size)

• The access to employment within a 30 minute transit ride of the

site.

• The size of households and their auto ownership

Variety of scale, mix, design

• 15 California sites

• 7 Florida sites (including ITE Trip Generation Handbook)

• 2 Texas sites

• 2 Utah sites

• 1 Georgia site

• 1 North Carolina site

28 NATIONWIDE VALIDATION SITES

Atlantic Station, Atlanta Uptown District, San Diego

Irvine, California Plano, Texas

Mixed-Use Centers, California and Florida

Celebration, Florida Otay Ranch, California

SOUTH DAVIS, CA

MORAGA, CA

Mockingbird Station, Dallas Bay Street, Emeryville, CA

MXD MODEL VALIDATION VS. COUNTED SITES

MXD MODEL COMPARED WITH ITE

ITE

MXD

Model Validation

UTAH VALIDATION CASE STUDIES

• Visited seven sites – Selected two sites

• Final sites chosen based on:

Sufficient mix of land uses

Feasibility of count data collection

SITE SELECTION – COUNTED SITES

Redstone Summit County

• 52 Acres

• 32,000 sf Office

• 20,000 sf Medical Office

• 210,000 sf Retail

• 8 Screen Movie Theater

• 320 Townhouse Units

Quarry Bend Sandy

• 100 Acres

• 450,000 sf Retail (includes Wal-

• 120 Apartment Units

• 275 Townhouse Units

• City Park

DESCRIPTION OF TWO SITES

REDSTONE

QUARRY BEND

11,000

11,500

12,000

12,500

13,000

13,500

14,000

14,500

15,000

ITE

ITE w/ Internal Capture

MXD Counts

Dai

ly V

ehic

le T

rip

s External Daily Vehicle Trips Comparison

Redstone

15% Reduction

DAILY TRIP COMPARISON

18,500

19,000

19,500

20,000

20,500

21,000

21,500

22,000

22,500

23,000

ITE

ITE w/ Internal Capture

MXD Counts

Daily V

ehic

le T

rips

External Daily Vehicle Trips Comparison

Quarry Bend

12% Reduction

DAILY TRIP COMPARISON

Extension of 7D Analysis to Austin,

Minneapolis, and Salt Lake Regions

Include All Trips from All Regions in Final

Modeling Exercise

Analyze All Catalytic Sites

New Tasks

There is a Better Way to Grow…

The Wasatch Choice

for 2040:

Regional Vision for

Land Use and

Transportation

There is a Better Way to Grow…

Focus growth in town centers, linked together with modern, efficient transportation systems.

Catalytic Sites

Provo Site

Key Downtown characteristics for 2040 growth

Downtown Provo Positioned to be Regional Economic and Cultural Center

Extension of 7D Analysis to Austin,

Minneapolis, and Salt Lake Regions

Include All Trips from All Regions in Final

Modeling Exercise

New Tasks