Traffic ReportC.E.S. NWInc.
Civil Engizzeeriyzg Services
May 8, 2001
Catherine Carlson, City Planner
City of Yelm
105 Yelm Avenue West
Yelm, WA 98597
Project: Autumn Hill (Lubbesmeyer Preliminary Plat)
Subject: Traffic Report
Dear Ms. Carlson:
5308 12~ Street East, Suite B
Fife, WA 98424
Phone: (253)922-1532
Fax: (253) 922-1954
This letter is to clarify the project name listed on the traffic report. The name of this
project was originally intended to be Prairie Heights. It was later discovered that the
neighboring development already had this name; therefore, the project name was changed
to Autumn Hill. However, the traffic study had been prepared prior to the project name
change. The close proximity of the original Prairie Heights to this project may cause
some confusion. Although the traffic study lists Prairie Heights, it was prepared for
Autumn Hill.
Sincerely,
Anna Holt
Project Engineer
~:~ HEATH & ASSOCIATES, INC. Transportation and Civil Engineering
PRAIRIE HEIGHTS
RESIDENTIAL SUBDIVISION
TRAFFIC ASSESSMENT
YELM, WA
'~-•~~ H I~olot
EXPIRES 6 30 01
Prepared for: Paul Lubbesmeyer
1151 East 112th Street
Tacoma, WA 98445
APRIL 2001
2214 Tacoma Road • Puyallup, WA 98371 • (253) 770-1401 • Fax (253) 770-1473
PRAII2IE HEIGHTS
RESIDENTIAL SUBDIVISION
TRAFFIC ASSESSMENT
TABLE OF CONTENTS
I. Introduction ................................................................................................................. 3
II. Project Description ......................................................................................................3
III. Existing Conditions .....................................................................................................3
IV. Future Traffic Demand ................................................................................................6
V. Conclusions and Mitigation ........................................................................................7
Appendix
LIST OF TABLES
1. Trip Generation ...........................................................................................................6
LIST OF FIGURES
1. Vicinity Map and Roadway System ...........................................................................4
2. Site Plan ......................................................................................................................5
3. Trip Distribution -Project Traffic ...............................................................................8
2
PRAIRIE HEIGHTS
RESIDENTIAL SUBDIVISION
TRAFFIC ASSESSMENT
I. INTRODUCTION
This study serves to investigate traffic impacts related to the proposed Prairie Heights
residential subdivision. The main goals of this effort focus on the assessment of existing
traffic conditions, forecasts of newly generated project traffic, and estimations of the
direction of travel. The first task includes the collection of general roadway information,
and entering sight distance data. Forecasts of future traffic and dispersion patterns on the
street system are then determined using established trip generation and distribution
techniques.
II. PROJECT DESCRIPTION
The proposed project is a residential subdivision comprised of 26 individual housing
units. Total site area is approximately 6.59 acres with an overall density of
approximately 4 units per acre. The site is located on the west side of Vancil Road south
of SR-507 in the City of Yelm, WA. Based on management projections, occupation of
this development could be anticipated by 2002 or 2003.
Figure 1 shows the general site location and roadway system and Figure 2 shows the
proposed site plan showing the overall lot configuration and internal roadway.
III. EXISTING CONDITIONS
A. Surrounding Roadway System
Roadways serving the proposed site range from two lane major arterials to two-lane
collector roads which vary in width, terrain, and posted speeds. These roadways vary in
their overall function as part of the general network. The key streets near the site are
described below.
South First Street is also the State Route 507. This is a two lane road, with a left turn
lane at the intersection with SR-510. The speed limit within the city is 25 mph, while to
the south the speed limit is 55 mph. Shoulders are roughly 5 feet wide and consist of
asphalt and grass or curb and sidewalk.
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SITE PLAN
FIGURE 2
Vancil Road SE is a two-lane roadway which lies along the east side of the property and
runs in a northerly direction toward SR-507. Lanes are 12 feet wide, while shoulders if
available are approximately 2 feet. Much of the roadway has been redeveloped to include
curb, gutter and sidewalk. Grades for the roadway are flat to slightly rolling (3 to 4
percent estimated) and the speed limit is posted as 25 mph.
B. Sight Distance at Accesses
Preliminary examinations of the proposed accesses onto Vancil Road SE were made to
determine whether or not adequate entering and stopping sight distance can be provided
for inbound and outbound project traffic. Based on field reviews, it appears that the
proposed access has sufficient available sight distance. No obstructions or horizontal or
vertical road curvature was noted at the entrance. The slight vertical curb to the north of
the entrances shouldn't impair sight distance. Once the actual location of the roadways
has been determined at the time engineering plans are approved, sight distance checks
could be made.
IV. FUTURE TRAFFIC DEMAND
A. Trip Generation
Trip generation is used to determine the magnitude of project impacts on the surrounding
street system. This is usually denoted by the quantity or specific number of new trips that
enter and exit a project during a designated time period, such as a specific peak hour or an
entire day. Data presented in this report was taken from the Institute of Transportation
Engineers publication, Trip Generation, sixth edition (LUC 210). Table 1 shows the trip
generation values used for this study. Included are the average weekday daily volume
and the AM and PM peak hour generation volumes for the proposed 26 dwelling units.
TABLE 1
Trip Generation Volumes
26 Units of
Time Period Single Family
Average Weekday Traffic 249 vpd
AM Peak Inbound 5 vph
AM Peak Outbound 15 vph
AM Peak Total 20 vph
PM Peak Inbound 17 vph
PM Peak Outbound 9 vph
PM Peak Total 26 vph
As shown in the table, the residential portion shows approximately 30 percent fewer trips
expected for the AM peak hour period compared to the PM peak. This is typical for
residential subdivisions where the discrepancy in morning and evening peak volumes is
6
somewhat noticeable. As is usually the case, the greater number of trips generated during
the PM peak are due to a higher number of personal trips such as recreation and
shopping.
B. Trip Distribution Pattern
Trip distribution describes the process by which project generated trips are dispersed on
the street network surrounding the site. Site generated trips are expected to follow the
trip pattern shown in Figure 3 on the following page. The distribution percentage is
based on the patterns which currently occur on the area roadways. Project traffic, being
primarily commuter oriented during the PM peak would follow the same pattern. As
shown in the figure, the distribution is split at SR-507 with 50 percent to and from the
southeast and 50 percent to and from the northwest.
V. CONCL USIONS AND MITIGATION
The Prairie Heights project will create 26 single-family residential lots with a single
access to Vancil Road. The site is located just to the southeast of downtown Yelm and
south of SR-507. This project is expected to generate an average of 249 residential trip
movements and during a typical weekday. An estimated 20 vehicle trips are associated
with the AM peak hour and 26 trips with the PM peak hour for the plat. Sight distance at
the project entrances appears to be adequate, based on a 25 mph speed limit.
7
PRAIRIE HEIGHTS
Summary of Trip Generation Calculation
For 26 Dwelling Units of Single Family Detached Housing
April 27, 2001
Average
Rate Standard
Deviation Adjustment
Factor Driveway
Volume
Avg. Weekday 2-Way Volume 9.57 3.69 1.00 249
7-9 AM Peak Hour Enter 0.19 0.00 1.00 5
7-9 AM Peak Hour Exit 0.56 0.00 1.00 15
7-9 AM Peak Hour Total 0.75 0.90 1.00 20
4-6 PM Peak Hour Enter 0.65 0.00 1.00 17
4-6 PM Peak Hour Exit 0.36 0.00 1.00 9
4-6 PM Peak Hour Total 1.01 1.05 1.00 26
AM Pk Hr, Generator, Enter 0.19 0.00 1.00 5
AM Pk Hr, Generator, Exit 0.58 0.00 1.00 15
AM Pk Hr, Generator, Total 0.77 0.91 1.00 20
PM Pk Hr, Generator, Enter 0.65 0.00 1.00 17
PM Pk Hr, Generator, Exit 0.37 0.00 1.00 10
PM Pk Hr, Generator, Total 1.02 1.05 1.00 27
Saturday 2-Way Volume 10.09 3.67 1.00 262
Saturday Peak Hour Enter 0.51 0.00 1.00 13
Saturday Peak Hour Exit 0.43 0.00 1.00 11
Saturday Peak Hour Total 0.94 0.99 1.00 24
Sunday 2-Way Volume 8.78 3.33 1.00 228
Sunday Peak Hour Enter 0.46 0.00 1.00 12
Sunday Peak Hour Exit 0.40 0.00 1.00 10
Sunday Peak Hour Total 0.86 0.95 1.00 22
Note: A zero indicates no data available.
Source: Institute of Transportation Engineers
Trip Generation, 6th Edition, 1997.
TRIP GENERATION BY MICROTRANS
Heath & Associates Inc.
Transportation Division
2214 Tacoma Road
Puyallup, WA 98371
(:rnnnc Printarl- 1 Inchiffari
File Name : 1629b
Site Code :00001629
Start Date :02/14/2000
Page No : 1
FIRST STREET YELM AVE S FIRST STREET YELM AVE
Southbound Westbound Northbound Eastbound
Start Time Ri ht Thru Left Ri ht Thru Left Ri ht Thru Left Ri ht Thru Left Int. Total
_
Factor 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
04:00 PM 28 15 28 20 124 23 22 15 7 3 107 28 420
04:15 PM 42 16 39 29 117 26 21 10 10 9 83 44 446
04:30 PM 49 22 42 26 125 24 23 10 11 6 91 40 469
04:45 PM 38 25 34 26 120 32 23 11 6 7 87 47 456
Total 157 78 143 101 486 105 89 46 34 25 368 159 1791
05:00 PM 60 20 32 26 117 28 25 11 11 ~ 8 77 41 456
05:15 PM 46 21 31 15 134 35 15 5 6 8 71 36 423
05:30 PM 27 9 21 17 124 29 18 13 8 4 101 35 406
05:45 PM 28 10 30 28 132 29 18 7 9 8 75 25 399
Total 161 60 114 86 507 121 76 36 34 28 324 137 1684
Grand Total 318 138 257 187 993 226 165 82 68 53 692 296 3475
Apprch % 44.6 19.4 36.0 13.3 70.6 16.1 52.4 26.0 21.6 5.1 66.5 28.4
Total % 9.2 4.0 7.4 5.4 28.6 6.5 4.7 2.4 2.0 1.5 19.9 8.5
FIRST STREET
In
Right Thru Lgk
T A
North
w <
m
14/00 4:00:00 PM ~-~ 3
w ~ 14/00 5:45:00 PM r-~2 ~
}~ i i ~ E`?b'm
I
i~ 5 73
Out In Total
Heath & Associates Inc.
Transportation Division
2214 Tacoma Road
Puyallup, WA 98371
File Name : 1629b
Site Code :00001629
Start Date :02/14/2000
Page No : 2
~ FIRST STREET YELM AVE S FIRST STREET YELM AVE
~ Southbound Westbound Northbound Eastbound
_
Start Time Right Thru Left App' Right Thru Left App' Right Thru Left App' Right Thru Left App. Int.
Total Total Total Total Total
Peak Hour From 04:00 PM to 05:45 PM -Pea
Intersection 04:15 PM
Volume 189 83 147 419
Percent 45.1 19.8 35.1
04:30 49 22 42 113
Volume
Peak Factor
High Int. 04:30 PM
Volume 49 22 42 113
Peak Factor 0.927
KlOrl
107 479 110 696
15.4 68.8 15.8
26 125 24 175
04:45 PM
26 120 32 178
0.978
92 42 38 172
53.5 24.4 22.1
23 10 11 44
30 338 172 540
5.6 62.6 31.9
6 91 40 137
1827
469
0.974
05:00 PM
25 11 11 47
0.915
04:45 PM
7 87 47 141
0.957
FIRST STREET
Right Thru Lgft
I w
North
w <
m
r
~ c~ 14/00 4:15:00 PM 4---~ ~
w ~ 14/00 5:00:00 PM ~
> ~ ~ ~ ~ m
I (~
® 1 0
Out In Total