Traffic Report 12-14-07
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TRAFFIC REPORT FOR
CROSSROADS OF CHANHASSEN
CHANHASSEN, MINNESOTA
CITY OF CHANHASSEN
RECEIVED
DEe 1 4: 2007
CHANHASSEN PLANNING DEPT
December 14, 2007
Prepared for:
Kraus-Anderson Realty Company
421 0 West Old Shakopee Rd.
Bloomington, MN 55437
Prepared by:
Westwood Professional Services, Inc.
7699 Anagram Drive
Eden Prairie, MN 55344
Phone 952-937-5150
Fax 952-937-5822
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BACKGROUND AND OVERVIEW
Kraus-Anderson Realty Company proposes to build a commercial development called
"Crossroads ofChanhassen" in the northwest quadrant of the intersection ofTH 101 (Great
Plains Blvd.) and CSAH 18 (Lyman Blvd.) in Chanhassen, Minnesota. (See Figure 1 - Site
Location Map.)
The proposed development is planned to include the land uses listed in Table 1. Access to the
site is planned from two full-access driveways, one on the east side onto TH 101 and the other on
the south side onto CSAH 18/Lyman. (See Figure 2 - Site Plan.)
Table 1
Proposed Land Uses
Land Use Size
Office Building 13,800 SF
Retail 47,400 SF
Drive-in Bank 5,000 SF
Gas Station with Convenience 10 Fueling
Store & Car Wash Positions
The opening of Highway 212 in December 2007 will impact the average daily traffic on TH 101
and Lyman Blvd. Prior to the opening, the existing average daily traffic by the proposed site on
TH 101 was 7,800 vehicles and on CSAH 18 was 5,800, according to MnlDOT 2005 figures.
(See Figure 3 - Average Daily Traffic.)
Page 2
Figure 1
Site Location Map
Page 3
Figure 2
Site Plan
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Figure 3
Average Daily Traffic
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ANALYSIS OF FUTURE CONDITIONS
TRIP GENERATION
A.M. and P.M. peak hour trip generation values were computed for these proposed land uses and
intensities using trip generation rates contained in the reference Trip Generation, ih Edition,
2003, published by the Institute of Transportation Engineers (ITE). Table 2 summarizes the trip
rates that were utilized for this study. Where available for a land use type and time period, the
fitted-curve equations were used. For the other uses and/or time periods, the average rate for that
use was applied. Table 3 summarizes the resulting gross trip generation.
A total of306 trips are projected to be generated in the A.M. peak hour, 839 in the P.M. peak
hour and 7,172 trip ends on a daily basis. In terms oftrip generation statistics, a "trip" is one
movement either into or out of the site. Therefore, a single truck or passenger vehicle creates
two "trips," one when coming to the site and a second trip when leaving.
I.T.E. A.M. Peak Hour P.M. Peak Hour Daily
Code land Use Units
Rate %In %Out Rate %In %Out Rate
710 General Office Building KSF 2.79 88 12 6.83 17 83 21.04
820 Shopping Center KSF 2.11 61 39 8.07 48 52 88.18
912 Drive-In Bank (by Sq.Ft.) KSF 12.34 56 44 45.74 50 50 233.71
946 Gasoline/Service Station with Fueling 10.64 51 49 13.33 50 50 152.84
Convenience Market & Car Wash Position
Table 2
Trip Generation Rates
Table 3
Gross Trip Generation
I.T.E. land Use Dev. Units A.M. Peak Hour P.M. Peak Hour Daily
Code In Out Total In Out Total Total
710 General Office Building 13.8 KSF 33 5 38 16 78 94 292
820 Shopping Center 47.4 KSF 61 39 100 184 199 383 4,180
912 Drive-In Bank (by Sq.Ft.) 5.0 KSF 35 27 62 115 114 229 1,170
946 Gasoline/Service Station with 10 Fueling 54 52 106 67 66 133 1,530
Convenience Market & Car Wash Positions
Gross Trip Generation 183 123 306 382 457 839 7,172
The trips shown on Table 3 represent the gross trip generation. This would be the expected level
of trips counted at the driveways of each of the land uses it they were individual, stand-alone
facilities. The actual new trips added by the development to the surrounding roadway system
will be lower than that for two reasons. First, in a commercial center such as this one, there is a
degree oftrip sharing and synergy amongst uses. The ITE Trip Generation Handbook suggests
guidelines for such retail to retail reductions. Because a single use (i.e., retail) constitutes a large
portion ofthe gross site trip generation, a conservative approach was utilized in which multi-
purpose trip reductions were applied only to the other uses on the site. In other words, the retail
trips remain at gross trip generation levels and it is assumed that 5% of visitors to the other site
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uses also have a linked trip with the general retail or with one another. These reductions are
shown on Table 4.
I.T.E. Land Use Dev. Units A.M. Peak Hour P.M. Peak Hour Daily
Code In Out Total In Out Total Total
710 General Office Building 13.8 KSF -2 0 -2 -1 -4 -5 -15
820 Shopping Center 47.4 KSF 0 0 0 0 0 0 0
912 Drive-In Bank (by Sq.Ft.) 5.0 KSF -2 -1 -3 -6 -6 -11 -59
946 Gasoline/Service Station with 10 Fueling -3 -3 -5 -3 -3 -7 -77
Convenience Market & Car Wash Positions
Multi-Purpose Trip Reductions -7 -4 -10 -10 -13 -23 -151
Table 4
Multi-Purpose Trip Reductions
A second reason why the trips are not all considered new trips is that many trips into the site will
be captured from vehicles already passing by the area on either TH 101 or CSAH 18. Statistics
collected by the Institute of Transportation Engineers indicate ranges for the values of the pass-
by percentages for different land use types. The ITE Trip Generation Handbook publishes
average rates of approximately 30% for retail, 45% for drive-in banks and 55% for gas stations,
which were used for their respective land uses. Table 5 shows the pass-by and diverted trips
calculated for this site. Table 6 shows the net new site trips which are assigned to the roadway
system.
Table 5
Pass-by and Diverted Trip Reductions
I.T.E: land Use De". Units A.M. Peak Hour P.M. Peak Hour Daily
Code In Out Total In Out Total Total
710 General Office Building 13.8 KSF 0 0 0 0 0 0 0
820 Shopping Center 47.4 KSF -18 -12 -30 -55 -60 -115 -1,254
912 Drive-In Bank (by Sq. Ft.) 5.0 KSF -15 -12 -27 -49 -49 -98 -500
946 Gasoline/Service Station with 10 Fueling -31 -29 -61 -35 -35 -69 -799
Convenience Market & Car Wash Positions
Pass-by Trip Reductions -64 -53 -118 -139 -144 -282 -2,553
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I.T.E. land Use Dev. Units A.M. Peak Hour P.M. Peak Hour Daily
Code In Out Total In Out Total Total
710 General Office Building 13.8 KSF 31 5 36 15 74 89 277
820 Shopping Center 47.4 KSF 43 27 70 129 139 268 2,926
912 Drive-In Bank (by Sq.Ft.) 5.0 KSF 18 14 32 60 59 120 611
946 Gasoline/Service Station with 10 Fueling 20 20 40 29 28 57 654
Convenience Market & Car Wash Positions
Net New Trips 112 66 178 233 300 534 4,468
Table 6
Net New Trips
TRIP DISTRIBUTION
The report "Traffic Study for Proposed Transit-Oriented Facility in City of Chanhassen"
(prepared by Benshoof & Associates, Inc., for Southwest Metro Transit, May 2004) was used as
a guide to the trip distribution for site traffic, as shown on Figure 4.
TRAFFIC ASSIGNMENT
Based on the trip generation and distribution, site traffic was assigned to the two access points
and to the intersection ofTH 101/ CSAH 18. (Site traffic is the gross trip generation minus
multi-purpose trip reductions.)
Figure 5 shows the A.M. peak hour, P.M. peak hour and daily site-generated traffic, including
the net trips and pass-by / diverted trips but not the multi-purpose trips. Figure 6 shows the net
new trips assigned to the system after taking reductions for pass-by and diverted trips, which are
vehicles already on the roadway.
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Figure 4
Trip Distribution
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Figure 5
Site-Generated Traffic
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Net New Trips
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CUT-THROUGH TRAFFIC
Concerns have been expressed regarding the potential of cut-through traffic through the proposed
Crossroads ofChanhassen development. Typically, cut-through traffic is of concern through
residential areas. Residential streets are not designed to carry high volumes of through traffic.
Unnecessary through traffic generates noise and is considered hazardous for residents, who will
object to the cut-through traffic. The potential for a small amount of cut-through traffic in a
retail area is ofless concern than for a residential area. Retail operators would not object to
small increases in traffic volumes adjacent to their facilities. As it is very difficult to quantify the
potential cut-through traffic, the following discussion provides qualitative comments.
The traffic movements of concern are for the southbound traffic on Highway 101 to westbound
on Lyman and eastbound on Lyman to northbound on Highway 101. The Crossroads
development will provide a slightly shorter alternative path than the County Roads. However,
the speed limits of 40 mph on Highway 101 and 50 mph on Lyman Boulevard are much higher
than the expected travel speed of 30 miles per hour through the site area.
Cut-through traffic typically tries to escape congestion on major streets. The level of congestion
is not expected to reach the high levels that would result in drivers seeking an alternative route.
The intersection of Highway 101 and Lyman Boulevard that could be avoided by a cut-through
is not expected to be a bottleneck with high delays for drivers. The lack of a high level of
congestion along the travel route greatly reduces the potential for cut-through traffic.
Alternative short-cut routes can sometimes save drivers time and frustration. The travel speeds
on the county roads will be much higher than speeds on the curvilinear road through the
development area. Even though congestion is not expected to be a problem through the site area,
the low speeds and frequent turns for drivers passing through the site area will not be conducive
to drivers seeking an alternative way to save time. It is very unlikely that drivers will save a
sufficient amount of time to justify the cut-through movement.
Traffic calming measures such as speed bumps could be applied to reduce the potential for cut-
through traffic. Additional stop signs could also reduce the attractiveness ofthe cut-through
route. These measures are currently considered unnecessary as the potential of cut-through
traffic is considered low. If cut-through traffic becomes a problem in the future, these measures
could be applied as needed to mitigate the problem.
SIGHT DISTANCE AND CIRCULATION
In order to achieve successful circulation around the gas station, two access points are required.
The site plan has been designed with one access at the northwest corner of the gas station site
and a second entrance at the southwest corner. This level of access is required to develop
efficient traffic circulation for vehicles using the fueling stations, parking adjacent to the store or
leaving the car wash. It is also needed to facilitate the movement of tanker trucks through the
site.
As part of the traffic analysis, the intersection sight distance was reviewed for the access point at
the northwest corner of the site. The traffic control at this intersection will include a stop sign
for traffic leaving the gas station and no control for movements along the site road. The
curvilinear nature of the site road, along with the close proximity to adjacent intersections, is
expected to result in travel speeds ofless than 30 miles per hour on the site drive. Sight distance
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requirements are reduced as speeds are lowered. The sight distance for a 30 mph roadway
ranges from a minimum distance of300 feet to an ideal distance of350 feet; with the expected
lower speeds an even lesser sight distance would be necessary. Obstructions to the driver's
vision must be avoided to provide sufficient site distance in the sight triangle area within the
minimum distance of300 and desired distance of350 feet.
CONCLUSIONS
. The Crossroads ofChanhassen site-generated traffic is about 7,000 gross trips per day. Net
new trips added to the roadway network total 4,470, with 1,790 allocated to/from north of the
site, 1,340 to/from the south, 450 to/from the east and 890 to/from the west. Site-generated
traffic is projected to be about 300 new trips in the A.M. peak hour and about 800 new trips
in the P.M. peak hour.
. The added volumes to the County Roads are relatively low. The County Roads will easily be
able to accommodate the additional traffic.
. The potential for cut-through traffic through the proposed site area is low and therefore is not
a concern.
. For sight distance considerations, it is important that vision not be blocked within a distance
of300 to 350 feet for drivers exiting via the site access at the northwest comer of the gas
station.
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