Walkable and Bikable Communities (WBC) Project WALKABILITY AUDIT INSTRUMENT 2 GIS_NEIGHBORHOOD_WALKABILITY_SCORE

Transcription

1 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 ; 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

2 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: NC 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 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.

3 WBC Walkability Audit Instrument 2 GIS_NEIGHBORHOOD_WAKLKABILITY_SCORE - WORKSHEET FOR SINGLE ENTRY (DRAFT) KEY ID ID Values to be filled in from GIS measurements Intermediate Variables (not included in the final computation) 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 >> Item SPATIAL OVERLAY with 1km Airline Buffer from Household Point Unit ENTER Default Bound (lower-upper) Current Condition ITEM EVALUATION O1 Total number of grocery stores or markets Count GOOD Fewer To Increase Walkability (Related Items) Shorter (A1) More (O3) O2 Total number of education land uses Count GOOD Fewer O3 Total number of NC_gro (grocery + restaurant + retail) Count OKAY More O4 Total number of residential units Count 7940 Shorter (A1) Fewer (O1) Q5 Total area of residential parcels Acre 1000 O6 Average net residential density within 1km airline buffer Units/Acre GOOD Lower More (P3) O7 Total sidewalk length within 1km airline buffer Feet ,716 POOR Longer AIRLINE DISTANCE From Household Point A1 To the closest grocery stores or markets Feet OKAY Shorter Fewer (O1) A2 To the closest school Feet 970 A3 To the closest eating or drinking place Feet GOOD Shorter More (O3) A4 To the closest NC_offmix (office + mixed use) Feet OKAY Longer NETWORK DISTANCE From Household Point N1 To the closest school Feet 1000 N2 Route directness between airline and network distance to the closest school Percent GOOD More Direct (Closer to 100%) SIMPLE PARCEL ATTRIBUTE P1 Total number of residential units in the household parcel Count 3 P2 Size of the household parcel Sq. feet P3 Residential units per acre for the household parcel Units/Acre POOR More P4 Size of the household block Acre ,600 OKAY Smaller DIGITIZATION & AREA CALCULATION D1 Size of the closest NC_off (office only) Acre GOOD Smaller

4 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 Closest School (Parcel Layer) Network (using the street networks) distance from the Household Point to the closest edge of the parcel that contain a school; See Additional Instruction 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.

5 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 ID Intermediate Variables (not included in the final computation) 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) Item SPATIAL OVERLAY with 1km Airline Buffer from Househod Point Unit No. 1 No. 2 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 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 Q5 Total area of residential parcels Acre O6 Average net residential density within 1km airline buffer Units/Acre 8 8 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! O7 Total sidewalk length within 1km airline buffer Feet AIRLINE DISTANCE From Household Point A1 To the closest grocery stores or markets Feet A2 To the closest school Feet A3 To the closest eating or drinking place Feet A4 To the closest NC_offmix (office + mixed use) Feet NETWORK DISTANCE From Household Point N1 To the closest school Feet N2 P1 Route directness between airline and network distance to the closest school SIMPLE PARCEL ATTRIBUTE Total number of residential units in the household parcel Percent #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! Count 3 3 P2 Size of the household parcel Sq. feet P3 Residential units per acre for the household parcel Units/Acre #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! P4 Size of the household block Acre DIGITIZATION & AREA CALCULATION D1 Size of the closest NC_off (office only) Acre 9 9

6 Columms Hidden >> No.19 No. 20 MEAN Default Bound (lower-upper) Current Condition GOOD Fewer GOOD Fewer GOOD More ITEM EVALUATION INSTRUCTIONS To Increase Walkability (Related Items) Overlay Between Additional Instruction Shorter (A1) More (O3) Shorter (A1) Fewer (O1) 1km Radius Airline/Circular Buffer from Household Point (called Buffer Layer), and Parcel Polygon Layers (called Parcel Layer) 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. Count NC2s (see Introduction for the definition of NC2) Total number of residential units (often available from the Parcel Layer's attribute data) that are within 1km from the Household Point Total area of parcels containing 1 or more residential units #DIV/0! #DIV/0! GOOD Lower More (P3) Automatic computation dividing O3 by the area of the buffer (approximately 801 acres) ,000 POOR Longer OKAY Shorter Fewer (O1) GOOD Shorter More (O3) OKAY Longer #DIV/0! #DIV/0! GOOD More Direct (Closer to 100%) Buffer and Sidewalk Line Total lengths of sidewalks within the Buffer (overlapping street segments are clipped to the buffer edge) Layers 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 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 the Closest School (Parcel Layer) Network (using the street networks) distance from the Household Point to the closest edge of the parcel that contain a school; See Additional Instruction 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 3.0 attribute Data The size of parcels that the Household Point is located #DIV/0! #DIV/0! POOR More Automatic computation dividing P1 by P ,600 OKAY Smaller Size of the street block where the Household Point is located GOOD Smaller Size of the closest NC8 polygon; this polygon can be digitized; See Additional Instruction for A4.

7 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 of the total 12 items performed better than the Default community OKAY of the total 12 items performed about the same as the Default Communuty POOR of the total 12 items performed poorer than the Default Communuty TOTAL 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

8 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 of the total 12 items performed better than the Default community OKAY of the total 12 items performed about the same as the Default Communuty POOR of the total 12 items performed poorer than the Default Communuty TOTAL 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