CHAPTER 1 - PURPOSE AND NEED
This chapter presents the need for increased north-south transportation capacity within
Tooele Valley and describes the project purpose. The Federal Highway Administration
(FHWA), the Utah Department of Transportation (UDOT), and Tooele County have
initiated this Environmental Impact Statement (EIS) to evaluate alternatives that would
improve north-south mobility in Tooele Valley. This EIS has been prepared in
accordance with the National Environmental Policy Act (NEPA) of 1969, FHWA’s
environmental regulations and guidance contained in 23 Code of Federal Regulations
(CFR) Part 771 and 7741 and Technical Advisory 6640.8A2, and to UDOT’s
environmental documentation standards. In addition, this EIS is consistent with Title VI
(sections 6001-6010) of the Safe, Accountable, Flexible, Efficient Transportation Equity
Act: A Legacy for Users (SAFETEA-LU), the most recent federal transportation
legislation passed in 2005.
1.1.1 Project Study Area
The project study area is located in the middle of Tooele Valley in Tooele County, Utah
(see Figure 1-1). In the west, the project study area extends approximately ¼ mile west
of Sheep Lane; in the east it extends about ¼ mile east of SR-36. The southern portion
of the project study area extends to the southern limits of Tooele City and the border of
the Tooele Army Depot (TEAD) along SR-112 and includes the Utah Industrial Depot.
The northern boundary of the project study area extends approximately ¼ mile north of I-
1.2 PROJECT NEED
The need for the Midvalley Highway is supported by previous studies and plans, and is
created by population growth in the area. As the population in Tooele Valley continues
to grow, increased traffic congestion will occur on the existing roadway network.
Transportation needs in Tooele Valley have been previously documented and evaluated.
Since the mid-1990s, five major studies or plans identify the need for increased north-
south transportation capacity due to increased travel demand. Prior planning studies
produced several alignments and alternatives within the project study area. The five
major studies that identify the Midvalley Highway project are discussed below.
Tooele County General Plan
The need for a new north-south transportation facility in Tooele Valley was first identified
in the Tooele County General Plan, approved in 19953. This general plan suggested two
options to improve congestion and safety problems. The first option was a belt route or
by-pass road to the west of Tooele City that connects to SR-36 north and south of the
City. A second option considered at that time was to convert Sheep Lane to an arterial
1 Environmental Impact and Related Procedures, and Parks, Recreation Areas, Wildlife, and Waterfowl Refuges, and Historic Sites
2 Guidance for Preparing and Processing Environmental and Section 4(f) Documents
3 Tooele County General Plan http://www.co.tooele.ut.us/PDF/General%20Plan/Chapter%2013.pdf
Chapter 1 – Purpose and Need Page 1-1 August 2009
road, extending it north to I-80 and south to the southern Tooele City limits through the
Tooele Army Depot.
Sheep Lane Study Report
The Sheep Lane Study Report, completed in 1999, was directed by Tooele County to
further study the transportation needs in Tooele Valley and to develop alternative
solutions to meet the needs previously identified. The study included extensive data
pertaining to existing transportation conditions, transportation needs, and a technical and
environmental review of identified alternatives. The report identified four new alignments
as possible solutions for improving regional congestion. The study recommended an
alignment along the existing Sheep Lane, with an extension to a new interchange at I-80
as the preferred alternative.
Transportation Infrastructure Requirements Study
In 2003 the Tooele Army Depot prepared the Transportation Infrastructure Requirements
Study. This study was initiated after the events of September 11, 2001 in response to
security issues at the TEAD. This plan was prepared to examine alternatives for the
south end of the project study area and concluded that the Tooele County’s north-south
transportation facility needed to be located outside of the TEAD. The study
recommended an alignment along SR-112 beginning near the Deseret Peak
Recreational Complex. The alignment would continue east toward Tooele City, then turn
south at the Utah Industrial Depot and connect to SR-36, south of Tooele City.
Tooele County Transportation Plan, update to the Tooele County General Plan
Tooele County Transportation Plan, Chapter 13 of the Tooele County General Plan was
amended in 2004. It included recommendations for improvements to Sheep Lane.
Consistent with the Sheep Lane Study Report, the Transportation Plan recommended
that Sheep Lane be widened and extended north to I-80 and south to SR-36 to relieve
congestion on SR-36 between I-80 and Tooele City.
Tooele Valley Long Range Transportation Plan
In October 2006, the Wasatch Front Regional Council (WFRC) prepared the Tooele
Valley Long Range Transportation Plan for the Tooele Valley Rural Planning
Organization, and developed seven alternatives to address the need for a new north-
south alignment. The plan identified two preferred alternatives: constructing a four-lane
highway along the Sheep Lane corridor, as well as the construction of the Adobe cutoff
interchange located west of Lake Point interchange. The Adobe cutoff alternative would
include a four-lane highway along the 1200 West corridor connecting to the new Adobe
Chapter 1 – Purpose and Need Page 1-2 August 2009
Exhibit 1-1 below summarizes past studies and their findings.
EXHIBIT 1-1, PAST STUDIES
The five reports above confirm the need to improve north-south transportation
infrastructure in Tooele Valley. Specifically, these studies support the need for
congestion relief on SR-36, and interchange solutions on I-80 to relieve anticipated
congestion at the Lake Point interchange.
1.2.1 Need for the Midvalley Highway
The need for increased north-south transportation capacity in Tooele Valley is
demonstrated by the following issues summarized in the bullets below and described in
more detail in this section.
• Population Growth – The population in Tooele Valley will nearly triple between
2006 and the design year 2030 (see Table 1-1). This population growth will
result in increased traffic demand that will overburden the existing and planned
Tooele Valley transportation network. In general, increased transportation
capacity is needed to relieve the projected traffic congestion.
• SR-36 Congestion – Specifically, the traffic analyses show that SR-36 will
become heavily congested and fail by the year 2030 if no improvements are
made beyond what is proposed in the Long Range Transportation Plan.
• Lake Point Interchange Congestion – The traffic analyses show that the
existing I-80 Lake Point interchange (SR-36 connection to I-80) will fail by the
18.104.22.168 Population Growth and Development
Rapid increase in population is expected to continue in Tooele Valley over the next 20
years. Based on population estimates developed by the Wasatch Front Regional
Council and data provided by the State of Utah Governor’s Office of Planning and
Chapter 1 – Purpose and Need Page 1-4 August 2009
Budget (GOPB)4, the Tooele Valley population is projected from 37,000 to over 98,000
by the year 2030. Table 1-1 shows the anticipated population growth in Tooele City,
Erda, Stansbury Park, and Grantsville.
TABLE 1-1, POPULATION FORECAST, 2006-2030
Location 2006 2030 Pop. Increase % Change
Tooele City 25,100 65,749 40,649 162%
Erda 1,450 10,343 8,893 613%
Stansbury Park 5,395 8,596 3,201 60%
Grantsville 5,352 13,736 8,384 156%
Source: WFRC with data provided by the Utah Governor’s Office of Planning and Budget:
The anticipated Tooele Valley growth will overburden the existing roadway network.
Without an increase or improvement in transportation capacity, the existing roadway
infrastructure will not be able to meet the future travel demands of the area. SR-36 is
the only arterial that leads north out of Tooele City with a direct connection to I-80. As
demonstrated later in this chapter, SR-36 is anticipated to fail by the year 2030.
Development trends and plans within Tooele Valley include large-scale residential and
commercial expansion within the next five to ten years (Tooele County, 2004).
Anticipated residential and commercial development within Tooele Valley is shown in
Figure 1-2. Much of this growth and expansion will occur within the limits of the project
study area. The Tooele Valley Regional Plan (Tooele County, 2003) shows that the
majority of the expected residential and commercial growth will occur northwest of
downtown Tooele City. With this growth, traffic volumes, congestion, and delays will
increase along the existing roadways.
Within Tooele City, the majority of the growth is expected to occur in the northwest part
of the city as stated above. The Tooele County General Plan states “growth in the city
(Tooele) is occurring through residential infill and outward growth in the northwest and
southwest quadrants of the city”. In Tooele Valley, large residential developments are
planned at Overlake Estates, Lake Point near I-80, Stansbury Park, and in the
southeastern quadrant of Grantsville.
• Overlake Estates within Tooele City – Overlake Estates is located directly
north of SR-112 and west of SR-36, as shown on the 2007 planned development
map from Tooele County. This is one of the largest developments in Tooele
Valley and is located in the northwest quadrant of Tooele City. It is about 2,700
acres in size; 615 of those acres are currently developed. In 2006, Overlake
Estates had a population of approximately 4,300 residents and is projected to
have 27,300 residents in 2030. This would equate to almost 40 percent of the
total Tooele City population in 2030. Overlake Estates planned development
4 The population information was used in the creation of traffic models for the Midvalley Highway and is used in this chapter for
Chapter 1 – Purpose and Need Page 1-5 August 2009
includes over 8,100 housing units, an eighteen-hole golf course, and other
• Erda Township – Erda is in the center of the project study area and has a
population of over 1,450. This area is expected to grow to more than 10,000
residents by the year 2030 (Tooele County, 2004).
• Stansbury Park – Stansbury Park is an improvement district that is part of the
county. This development is located toward the northeastern end of the project
study area and is approximately three miles from the Lake Point interchange via
SR-36. This development straddles SR-138, with the majority located on the
south side of SR-138. Stansbury Park is an unincorporated, planned
development and largely serves as a bedroom community to Salt Lake City and
the Wasatch Front. In 2006, Stansbury Park had a population of over 5,395 and
is anticipated to grow to 8,596 by the year 2030. The Stansbury Place
development, currently under construction, is planned to have a final build-out of
950 single family residences.
• Lake Point – Development in the Lake Point area is located on the east side of
SR-36. Lake Point development is in unincorporated Tooele County and is
planned for more than 2,000 homes (Tooele County, 2004).
• Eastern Grantsville – Grantsville’s east side is planned for commercial and
residential developments. Several large-scale developments are either occurring
or are in the planning stages in this area. South Willow Estates, a residential
community, is slated to include 450 houses. Oquirrh Estates is a high-density
affordable housing development with a mix of commercial and retail space. This
development is planned on 91 acres of land south of SR-138 and east of SR-112
in eastern Grantsville.
Chapter 1 – Purpose and Need Page 1-6 August 2009
The largest commercially developed area within the project study area is the Utah
Industrial Depot, located in the southwest quadrant of Tooele City. The Utah Industrial
Depot was once part of the Tooele Army Depot, but has been privatized and
incorporated into the Tooele City boundaries. The Utah Industrial Depot is home to
more than 60 individual businesses and manufacturing operations and is one of the
largest employers in Tooele County. The Utah Industrial Depot is approximately 1,700
acres in size and is planned to eventually have approximately 850,000 square feet of
industrial, commercial, and retail space and about 25,000 square feet of office space.
Other commercial areas within the project study area exist mainly in Tooele City, along
SR-36 and at the Lake Point interchange area near I-80. Even though it is outside the
project study area, a Wal-Mart Distribution Center is located west of Grantsville; it
employs about 700 workers. As pointed out by Tooele County planners, the area
adjacent to the Miller Motorsports Park and the Deseret Peak Recreational Complex, on
the western side of the project study area, has been zoned for commercial and industrial
development and is expected to develop within the next five years. Specifically, this
area has been zoned for “Technology Industries.”
Phase I of the Miller Motorsports Business Park has been approved by Tooele County.
This business park is located directly east of the Miller Motorsports Park (east of Sheep
Lane) and parcel 2 of this phase is currently under construction. Phase I of the Miller
Motorsports Park is approximately 126 acres in size.
The predicted increase in commercial development is expected to greatly increase
north-south traffic in Tooele Valley. The existing commercial truck traffic from the Utah
Industrial Depot currently uses SR-112/Utah Avenue5 to SR-36. The intersection of SR-
112 and SR-36 is located in downtown Tooele City and can be difficult to maneuver
because of the narrow roadway widths. The right-turn from southbound SR-36 to
westbound traffic on SR-112 is difficult for large commercial trucks, due to the lack of
22.214.171.124 Traffic Congestion and Failure on SR-36
SR-36 is the primary north-south arterial road in Tooele Valley; it serves as the primary
connection to I-80 for Tooele City and areas to the south (i.e. Stockton, Rush Valley),
Erda, Stansbury Park, the Tooele Army Depot, Utah Industrial Depot, Lake Point, Miller
Motorsports Park and the Deseret Peak Recreational Complex. SR-36 is two lanes from
the southern boundary of the project study area to 500 South in Tooele City; from 500
South to I-80 SR-36 is five lanes - two travel lanes in each direction with a center turn
lane. One of the core functions of SR-36 is to provide access to I-80 from population
areas within the project study area. Tooele City is approximately 11 miles south of I-80.
Level of Service on SR-36
Level of service (LOS) is a concept used by traffic engineers to measure how well a
transportation facility operates (i.e. how congested). LOS ranges from A (few cars on
the roadway) to F (congested – traffic levels exceed capacity). A description of the
different levels of service is included in Exhibit 1-2.
5 SR-112 is known as Utah Avenue from approximately 1000 West eastward in Tooele City.
Chapter 1 – Purpose and Need Page 1-8 August 2009
EXHIBIT 1-2, LEVEL OF SERVICE
The criteria used by transportation planners to determine LOS varies by the type of
roadway (e.g. arterials, freeways) and is found in the Highway Capacity Manual (HCM),
2000 published by the Transportation Research Board. Using the HCM arterials
planning methodology, Table 1-2 was developed for arterial type roadways such as SR-
36. This table shows the relationship between LOS, speed, and average daily traffic
volumes, measured in vehicles per day (vpd) for two-lane and four-lane arterials.
TABLE 1-2, LOS CRITERIA FOR ARTERIALS
Average Daily Traffic (vpd)
Level of Service Speed (mph)
2-Lane Arterial 4-Lane Arterial
A >42 <6,200 <14,600
B 34 – 42 6,200 – 15,000 14,600 – 32,000
C 27 – 34 15,000 – 16,100 32,000 – 34,100
D 21 – 27 16,100 – 17,400 34,100 – 36,800
Chapter 1 – Purpose and Need Page 1-9 August 2009
TABLE 1-2, LOS CRITERIA FOR ARTERIALS
Average Daily Traffic (vpd)
Level of Service Speed (mph)
2-Lane Arterial 4-Lane Arterial
E 16 – 21 17,400 – 19,200 36,800 – 40,500
F <16 >19,200 >40,500
Assumptions: 55 mph free flow speed, Class I arterial, 12% turns from exclusive lanes, 9.2% of daily traffic in the peak
hour, 70/30 directional split, 0.94 peak hour factor, one traffic signal per mile, 120 second cycle length, 0.50 effective green
ratio, and intersection arrival type 3.
Midvalley Highway EIS Traffic Report, April 2009
To determine what the roadway capacity needs are in the future, existing conditions are
compared to anticipated 2030 traffic demand. To better understand the existing
conditions within the project study area, traffic counts were conducted in May 2007 and
were used to estimate average weekday traffic volumes. To determine the LOS and
volumes along SR-36, it was divided into five segments (see Figure 1-3):
• Segment #1: Tooele Army Depot to 500 South located within Tooele City;
• Segment #2: 500 South to SR-112 (known as Utah Avenue within Tooele City);
• Segment #3: SR-112 to 2000 North (within Tooele City);
• Segment #4: 2000 North to SR-138; and
• Segment #5: SR-138 to I-80 (Lake Point interchange).
The five SR-36 segments were selected based on the existing number of lanes, existing
speed limits, and the types of adjacent land uses (i.e. segment #1 from the TEAD to 500
South has one lane in each direction, the speed limit ranges between 35-45 miles per
hour, and the adjacent land use is residential). Currently all of the SR-36 segments
within the project study area operate at an acceptable level of service. Table 1-3 shows
the existing number of lanes, traffic volumes and LOS.
TABLE 1-3, EXISTING SR-36 TRAFFIC VOLUMES AND ROADWAY LEVELS OF SERVICE
Number Level of
Segment # Location Along SR-36 Average Daily
of Lanes Service
#1 TEAD to 500 South 2 9,250 B
#2 500 South to SR-112 4 26,430 B
#3 SR-112 to 2000 North 4 32,170 C
#4 2000 North to SR-138 4 31,740 B
#5 SR-138 to I-80 4 27,510 B
Midvalley Highway EIS Traffic Report, April 2009.
Chapter 1 – Purpose and Need Page 1-10 August 2009
The Tooele Rural Planning Organization (RPO) Travel Demand Model was used to
develop and estimate the projected 2030 daily traffic volumes within the project study
area, specifically along SR-36. For the No Build scenario, it is assumed that only those
projects identified in the long range transportation plan will be constructed (see Chapter
2.0 – Alternatives Considered for a complete discussion on the No Build Alternative).
These roadways are included in the overall transportation network for developing the
SR-36 LOS and traffic volumes. In 2030, four of the five roadway segments along SR-
36 are anticipated to operate at LOS E and F for the No Build scenario. Table 1-4
illustrates the LOS for the 2030 No Build along SR-36.
TABLE 1-4, 2030 NO BUILD SR-36 TRAFFIC VOLUMES AND ROADWAY LEVELS OF SERVICE
Weekday Average Daily Traffic (ADT)
Segment Roadway 2030
# Segment LOS
Lanes 2007 between 2007 2030
#1 TEAD to 500 S. 2 9,250 6,450 18,700 C
#2 500 S. to SR-112 4 26,430 12,970 39,400 E
#3 SR-112 to 2000 N. 4 32,170 23,230 52,400 F
#4 2000 N. to SR-138 4 31,740 22,660 54,400 F
#5 SR-138 to I-80 4 27,510 26,890 54,400 F
Source: PB traffic counts, May 2007; PB Tooele RPO model runs, September 2007. See Exhibit 24 in the Midvalley Highway
EIS Traffic Report, April 2009.
Figure 1-4 shows the model results throughout the project study area. It shows that SR-
36 will fail if no improvements are made beyond what is planned. Increased north-south
capacity is required to meet the long term capacity needs for Tooele Valley and for SR-
36 to function at or above LOS D.
126.96.36.199 Traffic Congestion and Failure at the Lake Point Interchange
The existing interchange at Lake Point that connects I-80 with SR-36 currently operates
efficiently and has available capacity. The high volume movements are those from and
to the Salt Lake Valley located towards the east. Each of these ramps, from SR-36 to
east bound I-80 and west bound I-80 to SR-36, operates in a free-flow condition and
each has two lanes. However, the Tooele County Transportation Plan (Tooele County,
2004) states “the I-80 and SR-36 interchange (Lake Point) is not well suited for its
current and projected operational needs. It was designed for free movements between
south and east. With development that has occurred around the interchange,
operational problems are developing that should be corrected.”
According to the Highway Capacity Manual, a two-lane ramp with a free-flow speed of
40-50 mph has an approximate capacity of 4,100 vehicles per hour (vph). The existing
peak hour volumes on these ramps are between 1,800 and 2,200 vph, which is beneath
the available capacity. However, by 2030 the traffic volumes on these ramps are
projected to increase to between 4,200 and 4,800 vph, which exceeds the available
capacity and will fail if no improvements are made beyond what is planned.
Chapter 1 – Purpose and Need Page 1-12 August 2009
Other issues located near or at the Lake Point interchange include the configuration of
the I-80 frontage road (Clinton Landing Road) and its intersection with SR-36. The
spacing between the I-80 ramps and SR-36 limits the potential to accommodate
increased traffic demand. In addition, there are business accesses in this area that also
limit capacity between the ramps and the frontage road.
1.3 PROJECT PURPOSE
Given the needs described in section 1.2, the purpose of the Midvalley Highway is to:
• Provide increased north-south transportation capacity;
• Reduce anticipated congestion on SR-36 to LOS D; and
• Reduce anticipated congestion at the Lake Point interchange with I-80 to LOS D.
1.4 SUMMARY OF PURPOSE AND NEED FOR THE PROJECT
The population in Tooele Valley is expected to nearly triple by the year 2030. This is a
result of existing and planned residential, commercial, and industrial development. The
majority of the population growth within Tooele Valley is anticipated to be within the
project study area limits for the project. This large population growth will strain the
existing and planned transportation network within this area including SR-36 and the
Lake Point interchange with I-80. SR-36 is the major north-south transportation corridor
for Tooele City, Erda, Lake Point and other areas to the south. Currently, 11 miles of
SR-36 is a five-lane roadway extending south from I-80 to 500 South in Tooele City;
from 500 South southward, SR-36 is a two-lane road. The traffic analysis conducted for
this EIS shows that SR-36 fails and becomes congested by the design year 2030. The
Lake Point interchange also falls below the UDOT LOS standard by the design year
2030. Therefore, the needs for the Midvalley Highway are stated below.
• The existing and planned transportation network, including SR-36 and the Lake
Point interchange, will be congested with the rapid population growth;
• Anticipated traffic congestion on SR-36 will lead to an unacceptable LOS, and
will fail; and
• The Lake Point interchange will fail.
The purpose of the project includes adding increased north-south transportation capacity
in Tooele Valley, reducing future congestion along SR-36 between Tooele City and I-80,
and reducing future congestion at the Lake Point interchange at I-80. Tooele County
has been planning for a major north-south corridor as a result of the rapid population
growth and commercial development. The previous studies described above, confirm
that north-south transportation capacity is needed to address the congestion on existing
and planned roadways including SR-36 and the Lake Point interchange. This
Environmental Impact Statement has been prepared to address the purpose and need
as identified in this chapter.
Chapter 1 – Purpose and Need Page 1-14 August 2009