NCHRP Report 770: Estimating Bicycling and Walking for Planning and Project

Development

September 9, 2014

A Practitioner Guidebook on Methods for Estimating Bicycle and Pedestrian Demand

Product of NCHRP Project No. 08-78

Released August 2014

• Online PDF or hard copy

• CD_ROM with models

NCHRP Report 770

• Major gap in tools for bicycle and pedestrian planning

– Existing methods neither robust nor easy to use

– Seek greater parity with tools for motorized modes

• Key planning questions left unanswered: – Viability of Walk & Bike as transportation choices

– Impact on auto use & destination choice

– Support of smart growth land use concepts

– Support of transit (non-motorized access/egress critical)

– Most important & cost-effective facility improvements

NCHRP Report 770

• Lots of research – not so many useable tools

• Two primary existing options:

– Regional (TAZ-based) travel forecasting models

– Count- based Facility Demand models

• Bicycle and Walk very different modes & needs

• Non-motorized travel and land use highly inter-twined, need much finer scale of analysis

• Data challenges: counts limited (and limiting), behavioral data (travel surveys) scarce

NCHRP Report 770

• Take advantage of new data + special skills to try to quantify key relationships

– Recent travel surveys with good walk/bike samples

– Highly detailed parcel-level land use data

– Advanced GIS tools & data

• Priority: Behavioral framework

– Link “choice” to known causal factors

– Directly account for both land use and facilities

– Also traveler characteristics and trip purpose

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Predicts travel “tours” by purpose (7) and “simple” vs. “complex”

Mode choice (walk, bike, transit, auto) by purpose

Includes demographics, land use, facility characteristics, local & regional accessibility

Tour-Generation & Mode Choice*

Each model step sensi-tized to land use & accessibility

Inter-zonal mode split for bike, auto, transit Intra-zonal mode split for walk, bike, auto, transit

Includes demographics, land use, accessibility

Enhanced Trip- Based (TAZ) Model

Try to emulate Walk Score – almost entirely based on GIS

Compute accessibility scores for walk, transit, auto, (bike)

Relative scores translate to mode shares Highly visual/interactive

GIS Accessibility Approach*

Seattle/Puget Sound Arlington, VA

* = Spreadsheet version of model on CD-ROM

NCHRP Report 770

• Orientation to Bike/Ped planning issues

• Helpful facts on key relationships & factors

• Toolbox of models & techniques

• Detailed guidance on selection and use

NCHRP Report 770

NCHRP Report 770

• Land Use • Facilities • Natural Environment • Sociodemographic

Factors • Attitudes &

Perceptions

NCHRP Report 770

Used to Structure Modeling Framework

– Tour-based mode choice (Seattle)

– Enhancements for existing 4-step models (Seattle)

– GIS-based Accessibility Model (Arlington)

– MoPED and PedContext Walk Models (Maryland)

– Pedestrian Model Enhancement (Portland)

– Bicycle Route Choice models (San Francisco & Portland)

– Direct Demand (Santa Monica, San Diego)

NCHRP Report 770

– Modified four-step models

– “Pedestrian zones” in place of traffic zones (TAZs)

– Generates Walk trips (only), assigns to network

– Explain/predict choice of route

– Generated from GPS mapping of trips

– Account for facility type, grades, crossings, etc.

– Do not predict overall bike demand

NCHRP Report 770

Applicability Codes: Notes:

D = Direct role P = Partial role, can contribute 1 – Needs assignment program A = Key assisting role N = Not an obvious role 12

Disaggregate

Tour Based

(Seattle)

GIS-Based

Accessibility

(Arlington)

Enhanced

4-Step

(Seattle)

Portland

Pedestrian

Model

4-Step Walk

Models

(MoPeD)

4-Step Walk

Models

(PedContext)

Bicycle

Route

Choice

Direct

Demand

(St Monica)

Regional Plan

Development

D A D A A A P P

Scenario Planning/

Visioning

D D A A A A P P

Land Use/Smart

Growth/TOD

D D D A A A P P

Multimodal Corridor

Studies

D D A P A A A P

Traffic Impacts/

Mitigation

A A A P A A P P

Multimodal

Accessibility & Equity

D D A A A A A A

Local Comp or Master

Plans

D D A A A D A P

Site Planning &

Traffic Impact

Mitigation

D D A A D A A P

Bicycle or Pedestrian

Facility Planning

A1 A1 P P A D D D

NMT Facility

Prioritization

A1 A1 P A A D A A

Intersection Activity

Levels for Safety

Analysis

A1 A1 N P A D A D

NCHRP Report 770

• Geographic scale (regional, corridor, site)

• Applications

• Variables included in model structure

• Modeling steps included (e.g., mode choice)

• Key output indicators calculated

• Data requirements

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CD-ROM

• Unpublished Phase 1 Research Report – Detailed factors & trends

– Catalogue of models & research studies

– Data sources and issues

• Spreadsheet models

• Full technical model documentation

NCHRP Report 770

• Objectives:

– Build on the simplicity and appeal of Walk Score

– Seize on Accessibility approach to bring both Land Use and Network Connectivity into the equation

– Take maximum advantage of modern GIS capabilities

– Use visual properties to encourage stakeholder involvement and interaction

NCHRP Report 770

ACCESSIBILITY =

Number of Desired

Attractions

Impedance (Travel Time)

to Reach Attractions

“LAND USE” • Density • Diversity • Design

“NETWORK” • Connectivity • Directness • Safety

How much activity can I reach within a given travel time by each mode?

NCHRP Report 770

Overlay Networks and Land Use Features

NCHRP Report 770

A T B W

Modal Activity Ranges

Starting Point

Travel Time Decay Curve

Accessibility Score = Σ time-decayed opportunities

NCHRP Report 770

• Land Use: InfoUSA – Employment & # establishments by NAICS

– Exact x,y location

• Travel Networks: NAVTEQ – All streets, enhanced to include walk/bike facilities

– Path selection – Network Analysis (ArcGIS)

• Travel Behavior: – Travel survey data

– Trips with > 1 end in Arlington County

NCHRP Report 770

NCHRP Report 770

Comparative Accessibilities

Logan Circle Clarendon McLean

Auto 4.26 2.25 1.0

Transit 13.6 4.82 1.0

Bike 15.17 3.71 1.0

Walk 38.9 6.9 1.0

Non-Motorized Mode

Share

Logan Circle 41%

Clarendon 21%

McLean 8% NCHRP Report 770

NCHRP Report 770

Model Setup & Calibration

Travel Survey Trips

Calculate Accessibilities for Each

Trip End

Develop Mode Choice Equations

(curve fitting)

Model Application

Apply to Census Blocks

Calculate Accessibilities for Each Block (parcel)

Use Equations to Estimate Walk Ps & As,

trip table

NCHRP Report 770

Walk Score

100 300 500 700 900 1100 1300 All 100 300 500 700 900 1100 1300 All

Auto 685 68 24 16 25 8 30 856 237 97 61 55 43 37 326 856

Transit 260 57 23 16 25 14 30 425 54 16 7 19 18 10 307 431

Walk 12 7 3 4 12 3 6 47 6 5 3 6 7 4 16 47

957 132 50 36 62 25 66 1,328 297 118 71 80 68 51 649 1,334

Auto 72% 52% 48% 44% 40% 32% 45% 64% 80% 82% 86% 69% 63% 73% 50% 64%

Transit 27% 43% 46% 44% 40% 56% 45% 32% 18% 14% 10% 24% 26% 20% 47% 32%

Walk 1% 5% 6% 11% 19% 12% 9% 4% 2% 4% 4% 8% 10% 8% 2% 4%

Home Based Work (HBW) Origin Home Based Work (HBW) Destination

Mode Shares Mode Shares

Walk Score Walk Score

y = -0.126ln(x) + 1.2663R² = 0.8399

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Auto Mode Share

y = 0.0766ln(x) - 0.0497R² = 0.6348

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Transit Mode Share

y = 0.049ln(x) - 0.2166R² = 0.5669

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Walk Mode Share

y = 0.903e-3E-04x

R² = 0.6556

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Auto Mode Share

y = 0.1143e0.0008x

R² = 0.4996

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Transit Mode Share

y = 0.0181ln(x) - 0.0586R² = 0.2751

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Walk Mode Share

NCHRP Report 770

100 300 500 700 900 1100 1300 All 100 300 500 700 900 1100 1300 All

Auto 1,342 134 42 39 47 10 43 1,657 777 331 153 87 95 40 174 1,657

Transit 68 18 8 5 6 8 16 129 16 12 9 6 17 3 66 129

Walk 146 28 14 22 30 4 30 274 111 57 20 14 21 7 44 274

1,556 180 64 66 83 22 89 2,060 904 400 182 107 133 50 284 2,060

Auto 86% 74% 66% 59% 57% 45% 48% 80% 86% 83% 84% 81% 71% 80% 61% 80%

Transit 4% 10% 13% 8% 7% 36% 18% 6% 2% 3% 5% 6% 13% 6% 23% 6%

Walk 9% 16% 22% 33% 36% 18% 34% 13% 12% 14% 11% 13% 16% 14% 15% 13%

Home Based Non-Work (HBW) Origin Home Based Non-Work (HBW) Destination

Walk Score Walk Score

Mode Shares Mode Shares

y = -0.158ln(x) + 1.6157R² = 0.9539

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Auto Mode Share

y = 0.0502e0.0011x

R² = 0.4914

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Transit Mode Share

y = 0.0891ln(x) - 0.3206R² = 0.5847

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Walk Mode Share

y = 0.9074e-2E-04x

R² = 0.6389

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Auto Mode Share

y = 0.0169e0.0018x

R² = 0.8183

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Transit Mode Share

y = 0.1197e0.0002x

R² = 0.3762

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400

Walk Mode Share

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New Connections?

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• Hopefully an important step forward for bike/pedestrian planning

• Many questions can be better addressed:

– Role of land use, sensitivity to changes

– Role of facilities, most effective improvements

• More research, development, training needed

– Modeling bicycle demand

– Learning more about facility factors

– Putting a value on different land uses

NCHRP Report 770