Walkable and Bikable Communities (WBC) Project
WALKABILITY AUDIT INSTRUMENT 2
GIS_NEIGHBORHOOD_WALKABILITY_SCORE
Started Apr. 22, 2004: Last updated Apr. 8, 2005 Chanam Lee -default for Item A3 changed from 1090-1037; July 27
verified, Revised AVM Nov 2005
Purpose
This is a non-obtrusive tool to audit walkability. It is developed based on the results
from the Airline-based multinomial logit model estimating the odds of walking
sufficiently and moderately, relative to not walking. It includes 15 simple GIS
queries (than computes the total 12 evaluation items) that a GIS professional can
respond to using publicly available parcel and network GIS databases.
Responses are entered in the Worksheet that automatically computes the
expected probabilities of walking sufficiently, walking moderately, and not walking,
in the Evaluation sheet. There are two types, Single and Multiples, depending on
the number of points/households used for the audit.
Sampling of Household Points
Walkability of an area, such as a neighborhood and a city, is estimated by applying
the audits to samples of individual respondent home locations within the area of
interest.
Number of sample household points can range from a few to hundreds, depending
on the size of the area, target precision, etc. The rough rule is the more the better,
with a minimum about 1 household per 776 acres (3 sq. km.). Two methods can
be used for sampling:
■ a simple random sample of residential parcels
■ systematic samples taking points at every 1km interval
GIS Requirements
GIS System:
GIS Data:
GIS Techniques:
■ ArcView or ArcGIS
■ Parcel
■ Parcel data must include information on the following land use types: (a)
residential uses and number of residential units in the parcel, (b) grocery stores or
markets, (c) educational uses or schools, (d) retails, (e) restaurants, or eating and
drinking places, (f) offices, and (g) mixed-uses.
■ Street
■ Street block (size) - can be converted from the street layer, if not available
■ Sidewalk (length)
■ Buffering, overlay/clipping
■ Simple distance measurements, network-based distance measurements
■ Digitization
GIS Additional Data Preparations
Household Layer:
1. Using the parcel-level GIS data, identify a sample of household locations from
which the inventory will be conducted [make sure to use a Point layer to identify
the selected households]
Buffer Layer:
2. Create 1 km (0.62 miles) Airline and Network Buffers around each household
point
3. Identify the following types of Neighborhood Centers (NCs) that are touching or
within the Buffers [add an illustration]
■ NC_gro: Areas with at least one grocery store, one restaurant, and one
retail parcel within 50 meters (164 feet) of each other
■ NC_offmix: Areas with at least one office and one mixed use parcel within
50 meters (164 feet) of each other
■ NC_off: Areas with at least three office parcels within 50 meters (164 feet)
of each other
NC Layer:
Important Notes
■ This GIS_Neighborhood_Walkability_Score tool is designed to work in mediumto high-density residential communities with some commercial uses nearby. This
tool may not be applicable to low-density, rural areas, or areas with no commercial
activities.
■ One may choose to use the default values when the data are not available for
the particular item, but be aware that the default values are the mean values for
the urbanized King County areas of Washington State, that includes the City of
Seattle.
WBC Walkability Audit Instrument 2
GIS_NEIGHBORHOOD_WAKLKABILITY_SCORE - WORKSHEET FOR SINGLE ENTRY (DRAFT)
KEY
Values to be filled in from GIS measurements
ID
Intermediate Variables (not included in the final computation)
ID
Variables automatically caculated from Intermediate Variables
Variables used in the final probability estimation
"Current Condition" for each item automatically determined based on the difference between ENTER and Default values
"GOOD" : This item scored higher than the Default Communuty
"OKAY" : This item scored the same as the Default Communuty
"POOR" : This item scored lower than the Default Communuty
Columms Hidden >>
ENTER
SPATIAL OVERLAY with 1km Airline Buffer from
Household Point
Unit
O1
Total number of grocery stores or markets
Count
O2
Total number of education land uses
O3
ITEM EVALUATION
Default
Bound
(lower-upper)
Current
Condition
To Increase
Walkability
(Related Items)
1
3
0 - 18
GOOD
Fewer
Shorter (A1)
More (O3)
Count
3
5
0 - 46
GOOD
Fewer
Total number of NC_gro (grocery + restaurant + retail)
Count
2
2
0-6
OKAY
More
Shorter (A1)
Fewer (O1)
O4
Total number of residential units
Count
7940
Q5
Total area of residential parcels
Acre
1000
O6
Average net residential density within 1km airline buffer
Units/Acre
7.940
13.025
3 - 220
GOOD
Lower
More (P3)
O7
Total sidewalk length within 1km airline buffer
Feet
47000
52316
1500 - 122,716
POOR
Longer
1546
80 - 9843
OKAY
Shorter
Fewer (O1)
More (O3)
Item
AIRLINE DISTANCE From Household Point
A1
To the closest grocery stores or markets
Feet
1500
A2
To the closest school
Feet
970
A3
To the closest eating or drinking place
Feet
700
1037
50 - 9843
GOOD
Shorter
A4
To the closest NC_offmix (office + mixed use)
Feet
1100
1250
0 - 9843
OKAY
Longer
Feet
1000
Percent
97.0
73.860
20 - 100
GOOD
More Direct
(Closer to 100%)
Count
3
Sq. feet
11250
Units/Acre
11.616
18.138
0.8 - 680
POOR
More
Acre
10
7.700
0.7 - 11,600
OKAY
Smaller
Acre
9
12.099
0.3 - 1500
GOOD
Smaller
NETWORK DISTANCE From Household Point
N1
To the closest school
N2
Route directness between airline and network distance to
the closest school
SIMPLE PARCEL ATTRIBUTE
P1
Total number of residential units in the household parcel
P2
Size of the household parcel
P3
Residential units per acre for the household parcel
P4
Size of the household block
DIGITIZATION & AREA CALCULATION
D1
Size of the closest NC_off (office only)
INSTRUCTIONS
Overlay Between
Additional Instruction
Count parcels (not individual buildings/stores; one parcel with multiple stores/buidings is counted as one); Include parcels within and touching the Buffer
Layer; Count parcels with large chain and local grocery stores, and markets carrying all sorts of food products (e.g. fruits, vegetables, fish, etc.): Exclude
restaurants, liquor stores, bars, etc.
Include parcels with both public and private schools and universities: Exclude daycare, institutions, places of worship, etc.
1km Radius Airline/Circular
Buffer from Household Point Count NC2s (see Introduction for the definition of NC2)
(called Buffer Layer), and Parcel
Polygon Layers (called Parcel
Total number of residential units (often available from the Parcel Layer's attribute data) that are within 1km from the Household Point
Layer)
Total area of parcels containing 1 or more residential units
Automatic computation dividing O3 by the area of the buffer (approximately 801 acres)
Buffer and Sidewalk Line Layers Total lengths of sidewalks within the Buffer (overlapping street segments are clipped to the buffer edge)
Proximity
Airline (Straight Line) distance from the Household Point to the closest edge of the parcel that contain a grocery store or market; See Additional
Instruction of O1
From the Household Point to the Airline distance from the Household Point to the closest edge of the parcel that contain a school; See Additional Instruction of O2
Closest of Each Land Use Type
(Parcel Layer)
Airline distance from the Household Point to the closest edge of the parcel that contain an eating or drinking places, such as bars and restaurants
Airline distance from the Household Point to the closest edge of the NC5 polygon; NC5 polygon is the smallest polygon that encompasses all selected
land uses specified in the Introduction; this polygon can be digitized or visually approximated
Proximity
From the Household Point to the Network (using the street networks) distance from the Household Point to the closest edge of the parcel that contain a school; See Additional Instruction
Closest School (Parcel Layer) of O2
Automatic computation dividing A2 by N1, and then multiplying by 100 to get the percentage
Total number of residential units on the parcel that the Household Point is located; Directly taken from the Parcel Layer's attribute Data
The size of parcels that the Household Point is located
Automatic computation dividing P1 by P2
Size of the street block where the Household Point is located
Size of the closest NC8 polygon; this polygon can be digitized; See Additional Instruction for A4.
WBC Walkability Audit Instrument 2
GIS_NEIGHBORHOOD_WAKLKABILITY_SCORE - WORKSHEET FOR MULTIPLE ENTRIES (DRAFT)
KEY
Values to be filled in from GIS measurements
Mean values automatically calculated
ID
Intermediate Variables (not included in the final computation)
ID
Variables automatically caculated from Intermediate Variables
Variables used in the final probability estimation
"Current Condition" for each item automatically determined based on the difference between ENTER and Default values
"GOOD" : This item scored higher than the Default Communut
"OKAY" : This item scored the same as the Default Communut
"POOR" : This item scored lower than the Default Communut
ENTER START HERE (Add as many columes as needed)
SPATIAL OVERLAY with 1km Airline Buffer from
Househod Point
Unit
No. 1
No. 2
O1
Total number of grocery stores or markets
Count
1
0
O2
Total number of education land uses
Count
3
2
O3
Total number of NC_gro (grocery + restaurant + retail)
Count
2
3
O4
Total number of residential units
Count
7940
7940
Q5
Total area of residential parcels
Acre
1000
1000
O6
Average net residential density within 1km airline buffer
O7
Total sidewalk length within 1km airline buffer
Item
Units/Acre
8
8
Feet
47000
47000
No. 3
No. 4
No. 5
No. 6
No. 7
No. 8
No. 9
No. 10
No. 11
No. 12
No. 13
No. 14
No. 15
No. 16
No. 17
No. 18
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AIRLINE DISTANCE From Household Point
A1
To the closest grocery stores or markets
Feet
1500
1500
A2
To the closest school
Feet
970
970
A3
To the closest eating or drinking place
Feet
700
700
A4
To the closest NC_offmix (office + mixed use)
Feet
1100
1100
Feet
1000
1000
Percent
97
97
Count
3
3
NETWORK DISTANCE From Household Point
N1
To the closest school
N2
Route directness between airline and network distance to
the closest school
SIMPLE PARCEL ATTRIBUTE
P1
Total number of residential units in the household
parcel
P2
Size of the household parcel
P3
Residential units per acre for the household parcel
P4
Size of the household block
Sq. feet
11250
11250
Units/Acre
11.6
11.6
Acre
10
10
Acre
9
9
DIGITIZATION & AREA CALCULATION
D1
Size of the closest NC_off (office only)
Columms Hidden >>
ITEM EVALUATION
No.19
No. 20
MEAN
Default
Bound
(lower-upper)
Current
Condition
INSTRUCTIONS
To Increase Walkability
(Related Items)
Shorter (A1)
More (O3)
0.5
3
0 - 18
GOOD
Fewer
2.5
5
0 - 46
GOOD
Fewer
2.5
2
0-6
GOOD
More
Shorter (A1)
Fewer (O1)
3 - 220
GOOD
Lower
More (P3)
7940.0
Overlay Between
Count parcels (not individual buildings/stores; one parcel with multiple stores/buidings is counted as one); Include
parcels within and touching the Buffer Layer; Count parcels with large chain and local grocery stores, and markets
carrying all sorts of food products (e.g. fruits, vegetables, fish, etc.): Exclude restaurants, liquor stores, bars, etc.
Include parcels with both public and private schools and universities: Exclude daycare, institutions, places of worship,
etc.
1km Radius Airline/Circular
Buffer from Household Point Count NC2s (see Introduction for the definition of NC2)
(called Buffer Layer), and
Parcel Polygon Layers (called Total number of residential units (often available from the Parcel Layer's attribute data) that are within 1km from the
Household Point
Parcel Layer)
1000.0
#DIV/0!
#DIV/0!
7.9
47000.0
Additional Instruction
Total area of parcels containing 1 or more residential units
13.025
52316
1500 - 122,000
POOR
Automatic computation dividing O3 by the area of the buffer (approximately 801 acres)
Buffer and Sidewalk Line
Layers
Longer
Total lengths of sidewalks within the Buffer (overlapping street segments are clipped to the buffer edge)
Proximity
1500.0
1545
80 - 9843
OKAY
Shorter
Fewer (O1)
700.0
1037
50 - 9843
GOOD
Shorter
More (O3)
1100.0
1250
0 - 9843
OKAY
Longer
73.860
20 - 100
GOOD
More Direct
(Closer to 100%)
970.0
1000.0
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97.0
11250.0
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Automatic computation dividing A2 by N1, and then multiplying by 100 to get the percentage
Total number of residential units on the parcel that the Household Point is located; Directly taken from the Parcel Layer's
attribute Data
3.0
#DIV/0!
Airline (Straight Line) distance from the Household Point to the closest edge of the parcel that contain a grocery store or
market; See Additional Instruction of O1
Airline distance from the Household Point to the closest edge of the parcel that contain a school; See Additional
From the Household Point to
Instruction of O2
the Closest of Each Land Use
Airline distance from the Household Point to the closest edge of the parcel that contain an eating or drinking places, such
Type (Parcel Layer)
as bars and restaurants
Airline distance from the Household Point to the closest edge of the NC5 polygon; NC5 polygon is the smallest polygon
that encompasses all selected land uses specified in the Introduction; this polygon can be digitized or visually
approximated
Proximity
From the Household Point to
Network (using the street networks) distance from the Household Point to the closest edge of the parcel that contain a
the Closest School (Parcel
school; See Additional Instruction of O2
Layer)
The size of parcels that the Household Point is located
11.6
18.138
0.8 - 680
POOR
More
10.0
7.700
0.7 - 11,600
OKAY
Smaller
Size of the street block where the Household Point is located
9.0
12.099
0.3 - 1500
GOOD
Smaller
Size of the closest NC8 polygon; this polygon can be digitized; See Additional Instruction for A4.
Automatic computation dividing P1 by P2
WBC Walkability Audit Instrument 2
GIS_NEIGHBORHOOD_WAKLKABILITY_SCORE- EVALUATION FOR SINGLE ENTRY (DRAFT)
COMPOSITE PROBABILITY SCORE
An average person in this location/household is about:
35.2
% likely to walk sufficiently (150+minutes per week) in a usual week, enough for health benefits
63.1
% likely to walk moderately (1-149minutes per week) in a usual week, but not enough to achieve health benefits
1.8
% likely not to walk at all in a usual week
ITEM EVALUATION (Two columes under "ITEM EVALUATION" in "Worksheet")
Current
Condition
Number of
Items
Percent
GOOD
6
50.0
of the total 12 items performed better than the Default community
OKAY
4
33.3
of the total 12 items performed about the same as the Default Communuty
POOR
2
16.7
of the total 12 items performed poorer than the Default Communuty
TOTAL
12
100
USEFUL NOTES:
■ "Current Condition" for each item is automatically determined based on the difference between the entered and the
Default values.
■ Please note that the Item Evaluation is a relative evaluation based on the local Default Community,
which is considered to be fairly walkable (in this current Worksheet, the Default Community is a typical community in
medium to high density, urbanized areas in King County, Washington.
■ One can change the "Default" values to more meainingful target values for the particular community/city
■ Refer to "To Increase Walkability" column show what can be done to the particular item to increase walkability
■ Items with "POOR" indicate high priority areas for future intervention to increase walkability
WBC Walkability Audit Instrument 2
GIS_NEIGHBORHOOD_WAKLKABILITY_SCORE - EVALUATION FOR MULTIPLE ENTRIES (DRAFT)
COMPOSITE PROBABILITY SCORE
An average person in your community is about:
40.0
% likely to walk sufficiently (150+minutes per week) in a usual week, enough for health benefits
58.8
% likely to walk moderately (1-149minutes per week) in a usual week, but not enough to achieve health benefits
1.2
% likely not to walk at all in a usual week
ITEM EVALUATION (Two columes under "ITEM EVALUATION" in "Worksheet")
Current
Condition
Number of
Items
Percent
GOOD
7
58.3
of the total 12 items performed better than the Default community
OKAY
3
25.0
of the total 12 items performed about the same as the Default Communuty
POOR
2
16.7
of the total 12 items performed poorer than the Default Communuty
TOTAL
12
100
USEFUL NOTES:
■ "Current Condition" for each item is automatically determined based on the difference between the entered and the Default
values.
■ Please note that the Item Evaluation is a relative evaluation based on the local Default Community,
which is considered to be fairly walkable (in this current Worksheet, the Default Community is a typical community in medium
to high density, urbanized areas in King County, Washington.
■ One can change the "Default" values to more meainingful target values for the particular community/city
■ Refer to "To Increase Walkability" column show what can be done to the particular item to increase walkability
■ Items with "POOR" indicate high priority areas for future intervention to increase walkability