What’s a Pass-By Trip?
Shopping Center
Destination
Origin
Pass-By Trips
• Definition: Trips that would have traveled on
a street adjacent to a Retail Center even if
the retail was not constructed
• Applied only to retail-oriented land uses
–
–
–
–
–
Shopping centers
Convenience markets
Gas stations
Fast-food restaurants
Drive-in banks
• Results in reduction of new trips added to
network attributable to retail center
From
ITE
Handbook
Pass-by for Shopping Centers
20%
Pass-By Trips
• ITE Provides guidance on appropriate
percentages
– Shopping center percentages based on:
• size of retail space
• volume of adjacent street traffic (10% max)
Pass-by Reasonableness
Checks
• The number of pass-by trips should not
exceed 10 percent of the adjacent street
traffic during peak hour
• Strong justification must be provided to
document pass-by rates greater than 25
percent of the total external trip generation
for the developments retail portions
– Ensure proposed development displays ideal
characteristics to generate pass-by trips
10% of Adjacent Street Traffic
• Represents maximum number of trip ends
that can be subtracted from base trip
generation for pass-by analysis.
• Common misuse:
– Adjacent street traffic = 1000
– 10% = 100
– Those 100 vehicles enter the project, then exit
the project for a total reduction of 200 from
the trip generation
Driveway Traffic Will Include
All Of The Pass By Traffic
Beware when
analyzing
driveways:
analysis must
include passby trips in
driveway
volumes.
1,000
Pass-by Trips Example
Office
Apartment
Retail
Total Trip Generation
- Internal Capture
= External Trips
- Pass-by Percent
= External Trips
New to the
System
External Trips Worksheet
Retail
Office
TOTAL
Apartment
310
3740
745
4795
Exiting Internal Capture
26
19
43
62
107
131
Entering Internal Capture
52
42
66
13
107
131
Total Internal Capture
78
61
109
75
214
262
232
3679
670
4581
Total Trip Generation
0%
20%
0
0%
736
0
736
2943
670
3845
16.1%
232
External Trips Worksheet
Retail
Office
TOTAL
Apartment
310
3740
745
4795
Exiting Internal Capture
26
19
43
62
107
131
Entering Internal Capture
52
42
66
13
107
131
78
61
109
75
214
262
232
3679
3631
670
4581
4533
Total Trip Generation
- Total Internal Capture
External Trips
0%
- Pass-by Trips
20%
0
0%
736
0
736
2943
670
3845
16.1%
232
Shopping Center Pass-by Trips
Pass-by
Trips Example
Weekday, P.M. Peak Hour of Adjacent Street Traffic
Office
Apartment
Retail
20
Pass-by Percent
1000
20%
Pass-by Trips Worksheet
Retail
Office
TOTAL
Apartment
310
3740
745
4795
Exiting Internal Capture
26
19
43
62
107
131
Entering Internal Capture
52
42
66
13
107
131
Total Internal Capture
78
61
109
75
214
262
232
3679
3631
670
4581
4533
Total Trip Generation
External Trips
Pass-by Percent
Pass-by Trips
0%
20%
0
0%
736
726
0
736
726
2943
2905
670
3845
3807
16.1%
External Trips
New to System
232
Pass-by Check
91
957
23
Apartment
15
N
Apartment
47
Apartment
31
Apartment
Shopping
A
+
980
+
Office
=
287
+
+
Shopping
+
Office
=
34
Shopping
+
Office
=
+
Office
=
Shopping
Total
964
883
265
+
Pass-by Check
Total
302
Total
296
Total
2542
Total
Driveway
Volume
690+524+810+616=2,640 total background
Apartment
Apartment
B
+
+
Shopping
Shopping
167
167
+
Office
=
23+28
+
Office
2,640 x 10%=264 max pass-by
Total
51
=
Total
218
810
616
Total
Driveway
Volume
1543
Total
Total
393
304
Total
540
=
=
Shopping
354
265
Shopping
39
Apartment
Shopping
382
Apartment
39
19
Apartment
+
+
+
+
287
Shopping
19
Apartment
+
+
+
+
D
Office
Office
Office
139
=
Office
+
Shopping
+
Apartment
Shopping
+
C
+
Background
Traffic
=
=
=
Total
306
190
Total
Driveway
Volume
Total
Office
Total
23
Office
23
167
83+84
Background
Traffic
Apartment
690
524
Total
Driveway
Volume
87
Pass-by Check
91
N
726
Potential
Pass-by Trips
Retail
264
Max. Passby Trips
690
524
264
Total
Allowable
Pass-by
Trips
Background
Traffic
Background
Traffic
810
616
87
10%
OF BACKGROUND
Pass-by Trips Worksheet
Retail
Office
TOTAL
Apartment
310
3740
745
4795
Exiting Internal Capture
26
19
43
62
107
131
Entering Internal Capture
52
42
66
13
107
131
Total Internal Capture
78
61
109
75
214
262
232
3679
3631
670
4581
4533
Total Trip Generation
External Trips
Pass-by Percent
0%
20%
10%
backgrd
0%
(background)
Pass-by Trips
0
736
264
Actual Pass-by % of Retail 16.1%
External Trips
New to System
232
0
264 / 3631 =
2943
3367
670
736
264
7.3%
3845
4269