HomeMy WebLinkAbout1.01 Traffic Assessment Report
2667 Amber Spring Way
Grand Junction, CO 81506
970-314-4888
Traffic Assessment
Prepared for
Go Rentals
Container Storage & Equipment Rental
I -70 South Frontage Road, East of 16th St. (CR-311).
Silt, Colorado
January 15, 2025
1/15/25
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Table of Contents
Table of Contents
Table of Contents ........................................................................................................................ 2
List of Figures .............................................................................................................................. 2
List of Tables ............................................................................................................................... 2
1 Introduction & Methodology ............................................................................................... 3
2 Project & Access Descriptions ............................................................................................... 3
3 Existing Conditions .............................................................................................................. 5
4 Project Trip Generation, Distribution, and Assignment ......................................................... 6
5 Existing & Future Traffic Volumes ........................................................................................ 7
6 Turn Lane Warrant Analysis at Project Access ...................................................................... 8
7 Intersection Sight Distance .................................................................................................. 9
8 Access Permitting Considerations ...................................................................................... 10
9 Conclusions ........................................................................................................................ 10
Attachments
List of Figures
Figure 1 – Project Vicinity Map in Silt ................................................................................... 3
Figure 2 – Project Location Map .......................................................................................... 4
Figure 3 – Project Site Plan Concept ................................................................................... 4
Figure 4 – Study Area .......................................................................................................... 5
Figure 5 – Existing Site Access (MP 99.223R) .................................................................... 5
Figure 6 – Peak Hour Traffic Count at Site Access Point (AM/PM, vph) ............................. 7
Figure 7 – 2047 Total Peak Hour Traffic Volumes (AM/PM, vph) ........................................ 8
Figure 8 - View to West Along Frontage Rd. From Project Access ..................................... 9
Figure 9 – View to East Along Frontage Rd. From Project Access .................................... 10
List of Tables
Table 1 – Project Trip Generation by Phase ........................................................................ 6
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1 Introduction & Methodology
This report documents the Traffic Assessment (Study) for the proposed Go Rentals site
(Project) in Silt, Colorado. The Study Years were 2027 (Project buildout) and 2047 (20-
year condition). The analysis periods were the AM and PM peak hours. The following
sections describe the Project, traffic volume calculations, auxiliary turn lane warrants,
access spacing, and sight distance for the intersections in the Study Area.
2 Project & Access Descriptions
The Project would be located on the I-70 South Frontage Rd., east of 16th St. (CR-311),
as shown in the following figures. The site would be developed in two phases.
• Phase 1 in 2025 would include an equipment rental business in a 7,125 sf
building. There would be a 1,875-sf sales space and a 5,250-sf equipment
storage and maintenance shop.
• Phase 2 in 2027 would add 40 individual container storage units.
Figure 1 – Project Vicinity Map in Silt
PROJECT
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Figure 2 – Project Location Map
Figure 3 – Project Site Plan Concept
Existing
Access
Point
Existing
Access
Project
Site
Access
Owner
Site
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3 Existing Conditions
The Study Area included the intersection of I-70 South Frontage Rd. and the existing
site access.
Figure 4 – Study Area
Figure 5 – Existing Site Access (MP 99.223R)
The CDOT data site (OTIS) does not have information about frontage roads, but the
existing conditions and characteristics of this state highway include:
• Access Category: F-R
• Functional Class: Frontage Road
• NHS: No
• Speed Limit: 45 mph each direction
• ADT Estimate (based on recent peak hour traffic counts and a peak-daily factor
of 10): 800 vpd
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4 Project Trip Generation , Distribution, and Assignment
Project Trip Generation
The Project trip generation was partly based on the ITE Trip Generation rates and partly
by business operations information provided by the owner, due to unique business
characteristics. The attachments includes detailed information.
Phase 1 (2025)
Up to 10 employees would arrive in the morning peak and depart in the afternoon peak
hour. The rental business would operate for six days of the week and ten hours per
day. Up to 20 vehicles would arrive and depart randomly during the day. 17 (85%) of
these vehicles would be less than 20-ft long, with a passenger car equivalent (PCE)
factor of 1.0. Three (15%) of these vehicles would be 20-40 ft. long, with a passenger
car equivalent (PCE) factor of 2.0.This calculation assumed that 2 of these vehicles
would arrive and depart in the peak hour period.
ITE Land Use Code #811, “Construction Equipment Rental Store” has trip rates for the
PM peak hour only, based on building size. This calculation shows 7 total trips (2 in, 5
out), which was lower than the calculation based on owner information for this specific
visit. The ITE rates were not used in this calculation.
Phase 2 (2027)
In addition to the Phase 1 land use, Phase 2 would add 40 separate container storage
units in a cluster. The trip generation was based on ITE Land Use Code #151, “Mini-
Warehouse,” which is based on the number of storage units. There wouldn’t be any
storage trips in the AM peak hour and there would be 1 trip in/out during the PM Peak
hour. The following table shows the Project trip generation calculation for both phases,
in terms of PCE values.
Table 1 – Project Trip Generation by Phase
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Distribution & Assignment of Project Trips for Project Phase 2
The Frontage Rd. connects to the Silt Interchange located west of the Project. It was
assumed that 90% of Project traffic would travel to/from the west. There is an I-70
overpass, located east of the Project, that connects the South Frontage Rd. to US-6 on
the north side of I-70. It was assumed that 10% of Project traffic would travel to/from
the east.
The Phase 2 Projects trips were assigned to specific turning movements at the Project
Access, as follows:
• AM Peak Hour
o eastbound right turns inbound = 12 vph,
o westbound left turns inbound = 1 vph,
o northbound-to-westbound left turns outbound = 3 vph,
o northbound-to-eastbound right turns outbound = 0 vph.
• PM Peak Hour
o eastbound right turns inbound = 4 vph,
o westbound left turns inbound = 0 vph,
o northbound-to-westbound left turns outbound = 13 vph,
o northbound-to-eastbound right turns outbound = 1 vph.
5 Existing & Future Traffic Volumes
Existing Peak Hour Traffic Counts
The attachments include the peak hour traffic counts at the existing site access
intersection on the South Frontage Rd., taken December 10, 2024. As a road to local
businesses, there would not be a seasonal variation in traffic. Therefore, a peak season
adjustment factor was not applied to these traffic counts. The access currently services
the existing Solar Farm, which has little to no traffic due to minimal maintenance needs.
On this date, there were no trips to/from the Solar Farm.
Figure 6 – Peak Hour Traffic Count at Site Access Point (AM/PM, vph)
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Future Background Peak Hour Traffic Volumes on South Frontage Rd.
The CDOT database (OTIS) doesn’t have information about frontage roads. However,
the Colorado State Demography office provides population estimates through year 2050
(attached). This data indicates that the following population growth factors in Garfield
County would be appropriate. It was assumed that traffic growth would match population
growth. The following growth factors were applied to the traffic counts to obtain the
future background traffic volumes on the South Frontage Rd.
• 2027, use a 3-year growth factor of 1.030 (2024-2027) – not evaluated
• 2047, use a 23-year growth factor of 1.406 (2024-2047) - evaluated
Total Future Peak Hour Traffic Volumes at the Project Access -2047
Total traffic is the sum of project trips and future background traffic volumes.
Figure 7 – 2047 Total Peak Hour Traffic Volumes (AM/PM, vph)
6 Turn Lane Warrant Analysis at Project Access – Year 2047
The existing lane geometry was evaluated for the future 2047 condition. The
intersection is in CDOT Jurisdiction where the State Highway Access Code (SHAC)
applies. The Frontage Rd. has a speed limit of 45 mph in both directions. The access
category is FR (Frontage Road.). Auxiliary turn lanes on the Frontage Rd. would not be
required in the 2047 total traffic conditions.
• A westbound left turn deceleration lane would be warranted when the turning
movement has more than 25 vph, which would not be the case with 1 vph
projected in the future. In addition, the SHAC states that the need for a left turn
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lane could be waived if the westbound through traffic volumes were less than 100
vph, which would be the case in year 2047.
• An eastbound right turn deceleration lane would be warranted when the
movement has more than 50 vph, which would not be the case with 12 vph
projected in the future. In addition, the SHAC states that the need for a right turn
lane could be waived if the westbound through traffic volumes were less than 150
vph, which would be the case in year 2047.
• A northbound-to-eastbound right turn acceleration lane would be warranted when
the movement has more than 50 vph, which would not be the case with 1 vph
projected in the future. In addition, the SHAC states that the need for a right turn
acceleration lane could be waived if the westbound through traffic volumes were
less than 120 vph, which would be the case in year 2047.
• A northbound-to-westbound left turn acceleration lane would be warranted when
indicated by evaluation of a variety of factors. In addition, the SHAC states that
the need for a left turn acceleration lane could be waived if the westbound
through traffic volumes were less than 120 vph, which would be the case in year
2047.
7 Intersection Sight Distance
Another important element of intersection safety is sight distance for mainline traffic and
turning traffic. The Frontage Rd. is flat and straight. At 45 mph the required stopping
sight distance is 400-ft, and the required intersection sight distance is 585-ft. (2-lane
road & single-unit trucks) The following figures shows the sight distance in each
direction at the Project Access. Adequate sight distance is provided in both directions.
Figure 8 - View to West Along Frontage Rd. From Project Access
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Figure 9 – View to East Along Frontage Rd. From Project Access
8 Access Permitting Considerations
A CDOT Access Permit is necessary when the two-way traffic on the access point
changes by 20% or more, or access construction would occur. There would be a 20%
increase of traffic at this access so a CDOT access permit would be required. This is
an existing access so the permit would be for a change of use.
The Permittee would be the property owner of the adjacent parcel where the Solar Farm
is located. There is an existing cross access easement on the Solar Farm property for
the benefit of the Project property. The permitted traffic volume at MP 99.223 would be
18 vph for the 20-year condition.
9 Conclusions
The data and analysis in this Study supports the following conclusions:
1. The access point and the mainline would both have low traffic volumes.
2. The existing Project Access intersection would not need auxiliary turn lanes on
the Frontage Rd to accommodate existing or new Project traffic.
3. The intersection sight distance along the South Frontage Rd. is adequate.
4. One CDOT access permit for 18 vph would be necessary at MP 99.223 to
document the proposed change in traffic at the Project Access.
Attachments
• Peak Hour Project Trip Generation Calculations
• Traffic Count Data at existing Project Access
• Garfield County Population Estimates & Growth Factor Calculation