HomeMy WebLinkAboutA008 - Aspen Heights Traffic Impact Analysis Aspen Heights
Traffic Impact Analysis
Prepared for:
FOX Engineering
By:
Duane Smith, PE
desmith32(a-AOL.com
515-232-3202
February 19, 2014
C:\Users\Duane Smith\Desktop\Duane's Files\Traffic Engineering\1 Aspen Heights Development\TIA\TIA Report 2-19-14.docx
Table of Contents
Section Paqe
I. Introduction 3
A. Purpose
B. Analytical Process
II. Background 4
A. Aspen Heights Development
B. Location
C. Study Area
III. Site Trip Generation 7
IV. Directional Trip Distribution Middle and South Projects 7
V. Traffic Assignment 7
VI. Capacity Analysis 7
VII. TIA Conclusions 14
VIII Transportation Model 2035 17
IX Estimating Impacts in 2035 19
List of Figures
Number Title Paqe
Figure 1 Aspen Heights Location 5
Figure 2 Study Area 6
Figure 3 Trip Distribution 8
Existing, Site Generated and Combined Traffic Volume
Figure 4-6 Lincoln Way and Wilmoth Avenue 9
Figure 7-9 Lincoln Way and State Avenue 10
Figure 10-12 Lincoln Way and Hyland Avenue 11
Figure 13-15 Wilmoth Avenue and Tripp Street 12
Figure 16-18 State Avenue and Tripp Street 13
Figure 19-21 State Avenue and South Project 14
Figure 22-24 State Avenue and Mortensen Road 15
Horizon Year 2035
Figure 25 Transportation Model 2035 17
Figure 26 Lincoln Way and State Avenue percent growth 20
Figure 27 State Avenue and Mortensen Road percent growth 20
Figure 28 Lincoln Way and State Avenue 2035 Turning Movements 21
Figure 29 State Avenue and Mortensen Road 2035 Turning Movements 21
Figure 30 Lincoln Way and State Avenue 2035 Total Traffic 22
Figure 31 State Avenue and Mortensen Road 2035 Total Traffic 22
2 TIA Report 2-19-14
List of Tables
Number Title Page
Table 1 Site Generated Traffic 7
3 TIA Report 2-19-14
I. Introduction
A. Purpose
The purpose of this traffic impact analysis (TIA) is to forecast the travel demand and related traf-
fic impacts associated with the proposed Aspen Heights development projects. This develop-
ment is located on State Avenue, at the former Ames middle school site in Ames, Iowa.
The two (2) proposed Aspen Heights development projects discussed in this TIA are:
• the middle project located at the old Ames middle school site
• the south project located to the south of the middle project and north of Mortensen
Road, on the west side of State Avenue.
The results of the TIA will identify acceptable levels of service (LOS) and provide input regard-
ing traffic improvements that may be necessary to obtain acceptable levels of capacity in the
future. Roadway capacity is evaluated on the basis of a Level of Service (LOS) analysis. Levels
of Service are given letter designations of A through F, and are categorized based on driver
perception and ease of traffic movements. LOS A represents free-flow conditions with no de-
lays, while LOS E and F are generally considered unacceptable in urban areas.
B. Analytical Process
A detailed technical process was used in order to achieve the above objectives. Key
steps in the process include:
• Trip Generation —The product of the trip generation is the estimated number of trips to
and from each proposed land use within a development or project. Input includes statis-
tics on the proposed development (i.e. number of dwelling units, bedrooms, persons
etc.), and trip generation for each proposed use, (i.e. trips per person, etc.).
• Trip Distribution —The prime output of trip distribution is the quantification of the "desire"
to travel from one location (the origin) to another location (the destination). The % of trips
generated in the cardinal direction of north, south, east and west are documented. No
route or trip path is implied by the trip distribution process.
• Trip Assignment—The assignment process requires that a roadway network be identi-
fied such that each estimated trip generated can be assigned to a specific path (road-
way) connecting each origin-destination pair. The aggregation of all trips assigned to a
given link in the roadway link in the network is the final traffic forecast for the roadway
network.
• Capacity Analysis —This step consists of determining physical requirements needed to
accommodate the forecasted traffic volumes and the associated level of service (LOS).
The Synchro traffic modeling software, utilizing the Highway Capacity Manual (HCM)
methods, is a key tool in this step.
4 TIA Report 2-19-14
II. Background
A.Aspen Heights Development
The Aspen Heights development project has been detailed in the 321 and 601 State Avenue
master plans. The development is designed to be student apartments. The reason, it is ex-
pected that approximately 85% of the residents will be ISU students.
Trip Generation -Persons vs Dwelling Units
There may be a question concerning using persons and automobiles for the trip generation
analyses rather than the number of units. The following calculations illustrate that the number of
trips generated are similar when considering that the ITE trip generation rates are a result of
several studies and compiling data to establish those rates. The following calculations compare
traffic generated by persons and by dwelling units for the middle project
Persons Analysis:
The master plan shows 54 units. If we assume 3 persons per unit on the average there would
be 163 persons. Not everyone will have a vehicle and as a result, they will not be generating a
vehicle trip. This report assumes that 20 % of the people will not have a vehicle. Therefore, we
can reduce the number of persons by 20%. The calculations for daily trips would be:
(54 units) (3 persons per unit) (0.80) = 129 (assume 130 persons)
The ITE Trip Generation Manual code 220 Apartment indicates 3.31 trips per day per person.
(130 persons)(3.31) = 430 trips daily
Dwelling Units Analysis:
The master plan shows 54 units. The ITE Trip Generation Manual, code 220 Apartment as-
sumes 6.65 trips per day per unit.
(54 units)(6.65 trips per day) = 359 trips (assume 360)
If the number of trips is reduced by 20% because not all residents will have a vehicle, the num-
ber of daily trips is assumed to be:
(360 trips)(0.80) = 288.
Conclusion:
The conclusion that we can draw is that using persons as a metric to calculate vehicle trips is
more conservative than using dwelling units. As a result, this TIA will utilize the number of per-
sons (autos) as the basis for the analysis.
Establishing Maximum Number of Vehicles
The first step will be converting the number of bedrooms to persons and then to automobiles.
The middle site (321) is projected to include 150 bedrooms, and the south site (601) is projected
to include 570 bedrooms. The TIA will assume there is one (1) person per bedroom. The TIA
also assumes that there will be a maximum possible of one automobile for each person. There-
fore, the analysis will use a base of 150 persons (autos)for the middle project and 570 persons
(autos) for the south project.
5 TIA Report 2-19-14
Establish Vehicles for Trip distribution
The next step was to determine the number of automobiles that will be used in the trip distribu-
tion analysis. We know that not all students will have a vehicle. This fact reduces the traffic im-
pact the two developments will have on the adjacent street system. A study was completed on
January 23 and 24, 2013 at the Campus Crest apartment complex. The Campus Crest study
documents that approximately 20% of the occupants in that complex did not have a vehicle on
the site. The results of this study were used to discount the number of vehicles at Aspen
Heights by 20%. Therefore, the number of vehicles estimated for the Aspen Heights develop-
ment is 120 (150 x 80% = 120) for the middle project and 455 (570 x 80% = 456) for the south
project.
B. Location
The Aspen Heights development is located at the old Ames middle school site on State Avenue
in Ames, Iowa. It is divided into 3 projects. The north project is at the old track and field location
on Lincoln Way. The middle site is at the old middle school site and the south site is located
between the middle project and Mortensen Road on the west side of State Avenue. These pro-
jects are shown in Figure 1. Only the middle and south projects are included in this TIA.
North Project
I
Middle Project `
South Project '
I �
State Avenue
Figure 1 — Aspen Heights Project Locations
C. Study Area
The study area for this TIA was determined in consultation with the Ames City Traffic Engineer.
It was concluded that the intersections that are most likely to be impacted by the Aspen Heights
projects are: Lincoln Way and Wilmoth, Lincoln Way and State Avenue, Lincoln Way and Hy-
land Avenue, Wilmoth and Tripp Street, State Avenue and Tripp Street, State Avenue and
South Project entrance and State Avenue and Mortensen Drive. Surveillance cameras were
used to record traffic data at these intersections. The cameras recorded traffic data on Decem-
6 TIA Report 2-19-14
ber 3, 2013. Figure 2 below shows the intersections of interest and the location of the 5 surveil-
lance cameras.
... St r7-
s�
Figure 2 — Study Area
D. Background Traffic Volumes
The traffic counts used for background volumes were recorded by 5 cameras on December 3,
2013. The digital data from the cameras was used to determine hourly volumes, turning move-
ments and % cars and trucks at each intersection. In order to establish traffic peak flow periods,
data from Iowa State University was used. Iowa State University had completed a study in
April/May of 2013 at State Avenue and Mortensen Road. The ISU study identified the peak
hours as 8:00 — 9:00 AM and 4:30 — 5:30 PM. In order to utilize the traffic data from the camera
counts taken on December 3, 2013, the peak hours of 8:00 — 9:00 AM and 5:00 — 6:00 PM were
established for this TIA.
III. Site Trip Generation
Site trip generation refers to the relationship between vehicle trip making and land use activity.
Trip generation rates were taken from statistical studies of similar land use categories and doc-
umented by the Institute of Transportation Engineers (ITE). The application of these rates for
7 TIA Report 2-19-14
proposed land uses results in a travel demand which is then distributed by direction and as-
signed to the adjacent road network.
ITE's Trip Generation, Version 9 was used in this TIA to calculate expected trips generated by
the middle and south projects. ITE Code 220 Apartment was used to calculate vehicle trips.
Table 1 is a summary of the trip generation analysis.
Table 1 - Site Generated Traffic
AM Peak Rate PM Peak Rate AM Peak PM Peak Trips
Location ITE Persons Daily Daily Trips p
Code Rate Enter Exit Enter Exit Trips Enter Exit Enter Exit
Middle 220 120 3.31 0.14 0.16 0.24 0.26 400 16 20 29 31
Project p.345-6
South 220 455 3.31 0.14 0.16 0.24 0.26 1506 64 72 110 118
Project p.345-6
TOTAL 1906 80 92 139 149
IV. Trip Distribution
Trip distribution is the process of allocating the site generated trips to the street network and is
based on general location and direction of major population areas, employment, and commer-
cial hubs, combined with the availability of roadways to connect these attractions to the pro-
posed land development. The majority of the trips generated by the middle and south projects
will be directed to the north and south along State Avenue. There is more of a desire to travel
from the two projects south on State Avenue than to the north. The distribution shown in figure
3 illustrates that desire.
V. Traffic Assignment
Traffic assignment combines existing traffic volumes (the before condition) and the site generat-
ed traffic. The trips generated by the projects were added to the background volumes to esti-
mate the future (total) build out traffic volumes. Figures 4-24 illustrate the three traffic volume
components of traffic assignment; the existing, the site generated, and the combined traffic vol-
ume for each of the intersections included in this study.
VI. Capacity Analysis
Roadway capacity is evaluated on the basis of a Level of Service (LOS) analysis. Levels of
Service are given letter designations of A through F, and are categorized based on driver per-
ception and ease of traffic movements. LOS A represents free-flow conditions with no delays,
while LOS E and F are generally considered unacceptable LOS in urban areas.
The capacity analysis was conducted using Synchro traffic modeling software which follows the
Highway Capacity Manual (HCM) methods. For un-signalized intersections, LOS is given by mi-
nor street approach, and unlike signalized intersections, no overall level of service is given per
intersection. The LOS letter designation is shown in each of the intersection combined traffic
figures. The LOS designations appear as g�
8 TIA Report 2-19-14
r 8%
LINCOLN WAY r 2% I 6R r 2%
3% 24%, —1 f W
14% 26% Q
G
Z
40% g
s
LU 10% Vl
a r lo% J
_
ar- ARBOR ST 10%J
J 10%
3 W
~W
Vl a
5%
L 40%
10% L p% MIDDLE 50%J J
TRIPP ST 5%— r p% PROJECT 40%-} -1
50%
icmN
40%
60%J J
SOUTH
PROJECT 40%� --�
60R
20% 6% 14%
MORTENSEN RD --J L- L 30%
20%J f
10%
Figure 3. Trip Distribution Middle and South Projects
g TIA Report 2-19-14
Intersection Traffic Assignments
N WILMOTH AVE
2 0 0
J � L
of L8
LINCOLN WAY �A 685— —869 �B LINCOLN WAY
21-1 r 13
-, ,
5 2 6 6 (�tm„„
a
S WILMOTH AVE
Figure 4 Lincoln Way—Wilmoth Avenue Existing Traffic Volumes
N WILMOTH AVE
LINCOLN WAY 102— — 131 LINCOLN WAY
2-1 r 1
I ®moffffl
S WILMOTH AVE
Figure 5 Lincoln Way—Wilmoth Avenue Site Generated Traffic Volumes
N WILMOTH AVE
❑D
2 0 0
J I I
of LB
LINCOLN WAY ❑A 787— — 1000 FA LINCOLN WAY
231 r 14
5 2 6 6 tmm,
S WILMOTH AVE
Figure 6 Lincoln Way—Wilmoth Avenue Combined Traffic Volumes
10 TIA Report 2-19-14
LINCOLN WAY 776 —785 LINCOLN WAY
12- r 141
� 6 rF
9 173 MORrH
STATE AVE
Figure 7 Lincoln Way — State Avenue Existing Traffic Volumes
LINCOLN WAY LINCOLN WAY
1021 r 28
� 5 r
35 �
B2 PpIRM
STATE AVE
Figure 8 Lincoln Way — State Avenue Site Generated Traffic Volumes
LINCOLN WAY 776 —785 LINCOLN WAY
114—1 r 169
� 31 F
131 255 MORrH
STATE AVE
Figure 9 Lincoln Way — State Avenue Combined Traffic Volumes
11 TIA Report 2-19-14
HYLAND AVE
239 21 99
J I IL
❑A 209 J L 67 ❑B
LINCOLN WAY �A 558— —678 �B LINCOLN WAY
4, t 7 0
3 17 9 MORrH
HYLAND AVE
Figure 10 Lincoln Way — Hyland Avenue Existing Traffic Volumes
HYLAND AVE
I
100 J
LINCOLN WAY 155— —28 LINCOLN WAY
6-1 r2
2 8 1 ®MOM„
HYLAND AVE
Figure 11 Lincoln Way — Hyland Avenue Site Generated Traffic Volumes
HYLAND AVE
a
239 29 99
J � L
309 J L 67
LINCOLN WAY �A 713— —706 ❑B LINCOLN WAY
0 10-1 r9 0
7 --1 , r- F-
HYLAND AVE
Figure 12 Lincoln Way — Hyland Avenue Combined Traffic Volumes
12 TIA Report 2-19-14
S WILMOTH AVE
34 8
J
2,J
TRIPP ST �A
2-1
D 2 ®woerH
S WILMOTH AVE
Figure 13 Wilmoth Avenue — Tripp Street Existing Traffic Volumes
S WILMOTH AVE
26
TRIPP ST 3— —5 TRIPP ST
5 WILMOTH AVE
Figure 14 Wilmoth Avenue — Tripp Street Site Generated Traffic Volumes
S WILMOTH AVE
FA]
34 B 26
J � L
211 L o
TRIPP ST FA 5— —5 �A TRIPP ST
2-1 r 0
D 2 0 0 Mort�H
FA]
S WILMOTH AVE
Figure 15 Wilmoth Avenue — Tripp Street Combined Traffic Volumes
13 TIA Report 2-19-14
STATE AVE
422
I
215 twomm
STATE AVE
Figure 16 State Avenue — Tripp Street Existing Traffic Volumes
STATE AVE
16
J
16J
TRIPP ST
15�
5 ®woimH
STATE AVE
Figure 17 State Avenue — Tripp Street Site Generated Traffic Volumes
STATE AVE
FAIFA]
16 542
J
F23 J
TRIPP ST
18�
'
15 295 womw
FAIFA]
STATE AVE
Figure 18 State Avenue — Tripp Street Combined Traffic Volumes
14 TIA Report 2-19-14
STATE AVE
422
I
215 twomm
STATE AVE
Figure 19 State Avenue — South Project Existing Traffic Volumes
STATE AVE
80
J
120 J
SOUTH PROJECT
BO
120 tMORTH
STATE AVE
Figure 20 State Avenue — South Project Site Generated Traffic Volumes
STATE AVE
FAIFA]
80 422
J
❑d 120 J
SOUTH PROJECT
� I
120 230 womw
FAIFA]
STATE AVE
Figure 21 State Avenue — South Project Combined Traffic Volumes
15 TIA Report 2-19-14
STATE AVE
141 35 53
J � L
155 J L 82
MORTENSEN RD �C 287— —387 �E MORTENSEN RD
�C 8-1 r 12 Ffl
� 533 49 9
9 MORrH
STATE AVE
Figure 22 State Avenue — Mortensen Road Existing Traffic Volumes
STATE AVE
52 14 140
J I L
52 J L 36
MORTENSEN RD MORTENSEN RD
8 1 9 tmom
STATE AVE
Figure 23 State Avenue — Mortensen Road Site Generated Traffic Volumes
STATE AVE
193 49 193
J � L
❑E 207 J L 11a ❑s
MORTENSEN RD �C 287— —387 �E MORTENSEN RD
0 8 1 r 12 0
�53 138 9 MomH
a
STATE AVE
Figure 24 State Avenue — Mortensen Road Combined Traffic Volumes
16 TIA Report 2-19-14
VII. TIA Conclusions
Most every intersection in the study area will experience some changes in traffic vol-
umes as a result of these two projects. In almost all cases, changes in LOS are small
and will not be noticed by the traveling public. The intersection movements that show
the most changes are:
1. The signalized intersection of Lincoln Way and State Avenue is expected to have
some movements that are at LOS D but those are not changes from the current
condition. No improvements are recommended at this location.
2. The intersection of Lincoln Way and Hyland is expected to have some movements
that are at LOS D but those are not changes from the current condition. No im-
provements are recommended at this location.
3. The un-signalized intersection of Lincoln Way and Wilmoth is expected to experi-
ence a LOS of D for the northbound movement. No improvements are recommend-
ed for this movement. If the traveling public perceives that this is an unacceptable
LOS there are other routing options available.
4. The un-signalized intersection of State Avenue and the South Project entrance is
expected to function at an excellent LOS level except for the eastbound left and right
turn lanes. These two movements may function at a LOS of D. This should be ac-
ceptable since it is predicted to occur only during the highest travel time of the day
and only the residents of the development will experience this lower LOS. In many
urban areas LOS D is acceptable during peak traffic flow periods. No improvements
on State Avenue are required for this intersection.
5. In the future, the un-signalized intersection of State Avenue and Mortensen Road is
expected to experience low LOS for some traffic movements. Today, the intersec-
tion is experiencing low LOS conditions. The movements that are of concern for the
future are the eastbound, northbound and southbound traffic movements. Please
refer to figure 24. Major improvements to the entire intersection would be required in
order to provide a higher LOS. Planning activities for these improvements may in-
clude constructing a traffic roundabout or the installation of traffic signals. No im-
provements are recommended as a result of this study since the lower LOS condi-
tion exists today. The intersection LOS is considered to be a regional issue and not
an Aspen Heights project development driven issue.
VIII Transportation Model 2035
The city of Ames utilizes a transportation model to estimate transportation demands for
future dates. The Iowa Department of Transportation (DOT) manages this transporta-
tion model for the city of Ames. The DOT provided the transportation model values in
the study area for the year 2035. Please refer to figure 25 which illustrate the 2035
17 TIA Report 2-19-14
transportation model values. The model includes the "Existing + Committed + Planned"
roads. The model is showing adjusted traffic volumes for the Old Middle School loca-
tion. The transportation modeling engineer at the DOT thought the traffic volumes were-
n't showing as much growth on Lincoln Way as he would expect. After further analysis
he stated "I took a look at the counts from 1999 to 2011 in this area and there doesn't
seem to be much growth of traffic in the north half of the study area. More of the growth
from the base year counts seems to be towards the south part of the study area, which
the model shows as well." With the DOT transportation model engineer's statement we
can assume that the traffic volumes in the study area will show only modest, if any,
growth in the future. Therefore the LOS values would not be significantly different than
the values estimated in this TIA.
o'
LINCOLN WAY LIN�OLN WAY LINCOLN WAY I >
I0432 20 47 20139 m'
- - - - - - - - " -
p~
T
' < ARBOR ST WRBOR ST
S40 Bit
Pu
• m C "
> O
< z
m
KNAPP ST
SS41
�w
H
D
T
>
111
b
N>
w
rh
z
z
T
10
N
H
IOWA STATE UNIVERSITY' IOWA STATE UNIVERSITY
11296 _ 10765
M
m
Figure 25 Transportation Model 2035
18 TIA Report 2-19-14
IX Estimating Impacts in 2035
The following discussion will look at traffic projections for the target year 2035 and will
make a conclusion about the impact the Aspen Heights development may have in that
future year. The two intersections that will be most impacted by the Aspen Heights de-
velopment are Lincoln way / State Avenue and State Avenue / Mortensen Road. These
two intersections that were analyzed for the 2035 impacts.
The steps included in making the predictions for the target year of 2035 included:
1. Compare the existing traffic counts with the 2035 traffic model predictions and
establish a traffic growth relationship between the two. The DOT has existing
traffic counts in the study area and they were used to make the comparison.
From figure 25 the 2035 projected volumes were established. These values are
illustrated in figures 26 — 27. The percent change is shown in each of the figures.
The values are shows as : (2011 / 2035) XX%.
2. The next step is to apply the growth scenarios shown in figures 26 and 27 to the
estimated turning movements. The estimated turning movements are shown in
figures 3 and 22. Please refer to figures 28-29 for the turning movements that
have been estimated for the future year of 2035. A LOS has been calculated for
each of the intersection legs.
3. The site generated traffic volumes shown in figures 8 and 23 were added to the
2035 estimated turning movements. The resulting values are shown in figures
30-31. A LOS has been calculated for each of the intersection legs.
It would appear from the estimates for the year 2035 indicate the Aspen Heights devel-
opments will have approximately the same traffic impact on the study intersections as
they will when the projects are first developed. There will be a small increase in traffic
as a result of this development but that increase will not reduce the LOS to unaccepta-
ble levels.
The intersection of State Avenue and Mortensen Road as illustrated in figure 31 will
have several traffic movements predicted to be at LOS F. This condition will exist with-
out the Aspen Heights development. The reason this intersection is at such a low LOS
is because of it's role in the entire transportation system in southern Ames. The traffic
issues at this intersection are regional issues and not issues driven by the Aspen
Heights development projects.
19 TIA Report 2-19-14
LINCOLN WAY LINCOLN WAY
(17,000/20,247) + 20% (16,300/20,138) + 20%
(tNOFMI
(5200/4068) - 22%
STATE AVE
Figure 26 Lincoln Way and State Avenue percent growth
STATE AVE
(5200/4585) - 10%
MORTENSEN RD MORTENSEN RD
(13,200/11,296) - 15% (8,700/10,765) + 20%
(tNORiH
(1640/7221) + 340%
ESTIMATE + 10%
STATE AVE
Figure 27 State Avenue and Mortensen Road percent growth
20 TIA Report 2-19-14
LINCOLN WAY LINCOLN WAY
❑A 766+20%=930— 785+20%=940 �A
12+20%=15—� 141+20%=720
-1 r
1
II
O be
N p
I N
STATE AVE
Figure 28 Lincoln Way and State Avenue 2035 Turning Movements
0
o STATE AVE
to to
o b\
0 0
I
LO M
MORTENSEN RD J ") Lf MORTENSEN RD
155-15%=130 J L 82+20%=100
❑B 287-15%=245 — 387+20%=465 �F
8-15%=6 r 12+20%=15
C,7 I (t�NOFUH
to
O O 0
STATE AVE
Figure 29 State Avenue and Mortensen Road 2035 Turning Movements
21 TIA Report 2-19-14
LINCOLN WAY LINCOLN WAY
�A 930- - 940 �B
102—� 198
N
N WMTH
STATE AVE
Figure 30 Lincoln Way and State Avenue 2035 Total Traffic
STATE AVE
N 0
00 �t C)
MORTENSEN RD J �� L MORTENSEN RD
182 J L 136
❑D 245— — 465 �F
6- r 15
C,��t (t�NCWUH
aSTATE AVE
Figure 31 State Avenue and Mortensen Road 2035 Total Traffic
22 TIA Report 2-19-14