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MEMORANDUM
Date:
February 25, 2015
To:
Mike McCarthy, City of Tigard
Fred Gast, Polygon Northwest
Stacy Connery and Jim Lange, Pacific Community Design
From:
Julia Kuhn, PE
Project:
Bull Mountain Dickson
Estimated Local Street Volumes
Subject:
Project #: 13197
Polygon Northwest is proposing to develop the Bull Mountain Dickson neighborhood within the River
Terrace Community Plan Area. This new neighborhood will be located on the west side of SW 150th
Avenue opposite the SW Hawks Ridge Road. At this point, 82 detached single family homes are
proposed. The neighborhood will access SW 150th Avenue at two locations. SW Colorado Street will be
constructed opposite SW Hawks Ridge Road at the intersection with SW 150 th Avenue. SW Danube
Drive will access SW 150th Avenue to the north of SW Colorado Street.
The Bull Mountain Dickson neighborhood will include only the construction of local streets within its
boundaries. No collector streets or neighborhood routes are currently identified in the River Terrace
Community Plan on this property. The Plan does identify the extension of Woodhue Street from SW
150th Avenue west to the planned southerly extension of SW 161st Avenue. Although Woodhue Street
is south of the Bull Mountain Dickson neighborhood, the planned north-south local streets within the
neighborhood could extend south to Woodhue Street once the property to the south is developed.
As requested by the City of Tigard Planning Department, this memorandum provides an estimate of the
average daily traffic on SW Colorado Street and SW Danube Avenue, assuming development of both
the Bull Mountain Dickson neighborhood as well as the lands between this neighborhood and the
Woodhue Street extension. As will be discussed, both SW Colorado Street and SW Danube Avenue are
forecast to serve less than 1,000 vehicles per day once both neighborhoods are developed. Thus, both
streets are appropriate for the application of skinny street standards, per City of Tigard standards.
The remainder of this memorandum outlines our analyses.
Estimated Trip Generation
The estimated trip generation for the Bull Mountain Dickson neighborhood is shown in Table 1. Based
on information provided by Pacific Community Design staff, we also calculated the trip generation
associated with the potential buildout of the property between the new neighborhood and the
Bull Mountain Dickson
February 25, 2015
Project #: 13197
Page 2
Woodhue Street extension. The trip generation calculations are based on the rates included in the Trip
Generation Manual, 9th Edition (Institute of Transportation Engineers, 2012).
Table 1 Estimated Trip Generation
Land Use
ITE Code
Dwelling
Units
Total Daily
Trips
Weekday AM Peak Hour
Total Trips
In
Weekday PM Peak Hour
Out
Total Trips
In
Out
47
82
52
30
85
150
95
55
132
232
147
85
Bull Mountain Dickson
Single
Family
210
82
780
62
15
Potential Homes to the South
Single
Family
210
150
1,428
113
28
Total Both Areas
Single
Family
210
232
2,208
175
43
Estimated Local Street Average Daily Traffic (ADT)
As shown in Table 1, the combination of the two neighborhoods would result in a total of 2,208 new
daily trips. As noted above, these trips would access SW 150th Avenue via three locations: SW Danube
Avenue, SW Colorado Street and the Woodhue Street extension. Based on a review of proximity of the
houses to the three possible streets providing access to SW 150th Avenue, we estimate distribution of
the trips as follows:

SW Danube Avenue – approximately 50 of the Bull Mountain Dickson homes would use this
route to access SW 150th Avenue. This would result in approximately 476 average daily trips
using this roadway. No future neighborhoods are planned to access this street.

SW Colorado Street – approximately 32 of the Bull Mountain Dickson and 65 of the possible
150 homes to the south would use this route to access SW 150 th Avenue. This would result
in approximately 922 average daily trips using this roadway. No other neighborhoods are
planned to access this street.

Woodhue Street – approximately 85 of the homes to the south would use this route. This
would result in 810 average daily trips from the potential neighborhood to the south.
Woodhue Street will also facilitate trips from other homes within the River Terrace
Community area. The Transportation System Plan Amendment for River Terrace (DKS,
2014) evaluated the longer-term needs of Woodhue Street as a neighborhood route.
Therefore, no additional analysis is needed of this roadway at this time.
Kittelson & Associates, Inc.
Portland, Oregon
Bull Mountain Dickson
February 25, 2015
Project #: 13197
Page 3
Conclusions
Based on the above analysis, both SW Danube Avenue and SW Colorado Street are estimated to carry
less than 1,000 vehicles per day at full buildout of both Bull Mountain Dickson and the potential lands
to the south of the neighborhood and north of the Woodhue Street extension. Based on City of Tigard
standards, the volume associated with both streets is appropriate for the application of local street
standards.
Please let us know if you have any additional questions.
Kittelson & Associates, Inc.
Portland, Oregon