NCHRP 08-78
Renaissance Planning Group
Rich Kuzmyak
Chris Sinclair
Alex Bell
TRB National Transportation Planning
Applications Conference
May 6, 2013
Columbus, Ohio
 Research
context
 Basics of the accessibility approach
 Summary of research findings
 Application
 Next steps
 NCHRP
8-78: Estimating Bicycle and
Pedestrian Demand
 Create new methods – sensitive to land
use and facilities
 Product: Practitioner Guidebook of
scalable techniques
• Tour-based models (Seattle – Bradley & Bowman)
• Enhanced 4-step (Seattle – Kockelman & Kahn)
• Accessibility approach (Arlington VA)
 Travel
behavior is responsive to
“accessibility”
 Mode choice can be linked to:
• Amount of activity reachable from an origin over
corresponding modal network
• Account for impedance unique to mode
(directness, slope, facility type, etc.)
 Use
detailed travel networks to model
travel times from a given origin to all
accessible destinations (by mode):
• Walk
• Bike
• Transit
• Auto
 NAVTEQ
streets, GTFS transit schedules,
bicycle facilities and trails
SAMP 2191645
Walkable - Ballston
HH AT LINK 18422512
Impedance Rings
5 Minutes
Cumulative
10 Minutes
Cumulative
15 Minutes
Cumulative
20 Minutes
Cumulative
25 Minutes
Cumulative
30 Minutes
Cumulative
SAMP 2267554
Non-Walkable
HH AT LINK 113364195
Impedance Rings
5 Minutes
Cumulative
10 Minutes
Cumulative
15 Minutes
Cumulative
20 Minutes
Cumulative
25 Minutes
Cumulative
30 Minutes
Cumulative
Walk
Total
Employment
Bike
Grocery
Locations
50
50
5,526
5,576
21,276
26,852
3,827
30,679
2,202
32,881
2,701
35,582
Total
Employment
0
0
4
4
9
13
10
23
2
25
4
29
9
9
57
66
5
71
15
86
26
112
222
334
Grocery
Locations
24,114
24,114
10,164
34,278
13,654
47,932
29,089
77,021
41,228
118,249
23,373
141,622
Walk
Total
Employment
Auto
Total
Employment
10
10
16
26
23
49
71
120
45
165
32
197
59,388
59,388
268,845
328,233
634,064
962,297
310,038
1,272,335
349,918
1,622,253
431,120
2,053,373
Bike
Grocery
Locations
Total
Employment
0
0
0
0
0
0
1
1
0
1
0
1
71
71
73
144
324
468
1,619
2,087
1,089
3,176
4,216
7,392
Grocery
Locations
85
85
253
338
481
819
454
1,273
555
1,828
587
2,415
Auto
Grocery
Locations
Total
Employment
0
0
1
1
3
4
1
5
1
6
3
9
4,515
4,515
37,662
42,177
27,288
69,465
17,618
87,083
102,806
189,889
118,282
308,171
Grocery
Locations
6
6
59
65
49
114
51
165
113
278
169
447
Total Employment - Walksheds
40,000
160,000
35,000
140,000
30,000
120,000
25,000
100,000
Ballston
20,000
Total Employment - Bikesheds
Ballston
80,000
Suburbs
15,000
60,000
10,000
40,000
5,000
20,000
0
Suburbs
0
0
10
20
30
40
0
10
20
Total Employment - Drivesheds
2,500,000
2,000,000
1,500,000
Ballston
Suburbs
1,000,000
500,000
0
0
10
20
30
40
30
40
 Non-motorized
trip making is associated
with high accessibility scores, regardless
of mode
 Modal competiveness (in terms of
accessibility) influences mode choice
• More transit trips are made to destinations that
have high walk and transit accessibility scores
• Discretionary walk trips are highly sensitive to
walk accessibility at the trip origin
• Walk to work a unique/limited opportunity
Number of Establishments Accessible from Origin
Chosen Mode
Auto
Transit
Walk
Bike
Transit
1367
129
109
1162
Drive Alone
1195
69
60
868
Auto Pax
1177
66
57
840
Walk
1345
124
98
998
Bicycle
1506
120
91
1191
Number of Employees Accessible from Origin
Chosen Mode
Auto
Transit
Walk
Bike
Transit
18110
1650
1457
13986
Drive Alone
15092
984
797
10783
Auto Pax
13658
840
673
9254
Walk
23583
2962
2329
15778
Bicycle
19516
1470
1237
14845

Walk accessibility alone influences mode choice
Auto
Transit
100%
Auto
80%
Log. (Auto)
100%
60%
60%
40%
40%
20%
20%
0%
>200
200
400
600
800
1000 1200+
Transit
80%
Log. (Transit)
0%
>200
200
Bike
5%
600
800
1000 1200+
Walk
50%
Bike
4%
400
Walk
40%
Log. (Bike)
3%
30%
2%
20%
1%
10%
0%
Log. (Walk)
0%
>200
200
400
600
800
1000 1200+
>200
200
400
600
800
1000 1200+
GIS
SELECTION
TOOL
Identify Study Area
(parcels/blocks/TAZs)
Identify Walkshed
(area within 30 min walk)
TRIP
GENERATION
RATES
WALK
NETWORK
& SKIMS
Compile SEDs for Walkshed
DUs: SF and MF
EMP: IND, COM, SVC
Person Trip Generation
Productions & Attractions
for HBW, HBO, NHB
Walk Score Calculation
For each parcel as an
origin and destination
Walk Trip Generation
Convert person trip P’s &
A’s to Walk P’s & A’s
Walk Trip Tables
Balance Walk P’s & A’s
for Walkshed by Purpose
USER DASHBOARD
(summary of inputs and
outputs comparing
scenarios)
WALK SCORE
MODE SPLIT
CURVES
 Spreadsheet
tool (beta version and
template for additional tools)
 Models
effects of…
• Land use changes
 Development master plans
 Disaggregated TAZ forecasts
 Future land use scenarios
• Network enhancements
 Accessibility benefits of improving street connectivity
 Non-motorized facilities
 Data
and process
• Microzone residential and employment activity
 Person trip generation
• Zone to zone walk skims (microzones)
 Walk accessibility score
 Output
• Microzone walk trip generation
• Matrix of walk microzone to microzone walk trip
interchange
 Develop
native GIS tool
• Community Viz or other scenario planning platform
• Enable dynamic spatial analysis
 Evaluate
and operationalize relationships
among modal accessibilities and sociodemographics
• High local walk access, low regional transit access
vs. High local walk access, high regional transit
access
• Household and individual characteristics
 Incorporate
into NCHRP Guidebook
 Integrate with regional travel demand
model
 Incorporate EPA’s Smart Location
Database modal accessibilities and add
geoprocessing services to support rapid
deployment of the tool
 Thanks!