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Marsh Oaks Development
Traffic Impact Analysis
New Hanover County, North Carolina
TRAFFIC IMPACT
ANALYSIS
FOR
MARSH OAKS DEVELOPMENT
LOCATED
IN
NEW HANOVER COUNTY, NORTH CAROLINA
Prepared For:
Vanguard Property Group
3825 Barrett Drive, Suite 100
Raleigh, NC 27609
Prepared By:
Ramey Kemp & Associates, Inc.
5808 Faringdon Place, Suite 100
Raleigh, NC 27609
License #C-0910
MAY 2022
RKA Project No. 21774 Prepared By: TF
Reviewed By: CC
5/18/2022
TRAFFIC IMPACT ANALYSIS
MARSH OAKS DEVELOPMENT
NEW HANOVER COUNTY, NORTH CAROLINA
EXECUTIVE SUMMARY
1. Development Overview
A Traffic Impact Analysis (TIA) was conducted for the proposed Marsh Oaks development in
accordance with the Wilmington Urban Area Metropolitan Planning Organization (WMPO) and
North Carolina Department of Transportation (NCDOT) capacity analysis guidelines. The
proposed development is to be located along US 17 (Market Street) and Marsh Oaks Drive in
New Hanover County, North Carolina. The proposed development is expected to consist of
10,200 square feet (s.f) of medical-dental office, 6,300 s.f. of strip retail plaza, and 2,400 s.f. of high-
turnover sit-down restaurant and is estimated to be built-out in 2023. Site access is proposed via
one (1) full movement driveway along Marsh Oaks Drive as well as one (1) right-in/right-out
(RIRO) driveway on US 17 (Market Street). The full movement driveway on Marsh Oaks Drive is
proposed to be aligned with the Amberleigh Shores Driveway. It should be noted that these
driveway connections are expected to be constructed by the Primrose School of Mayfaire
development.
The study analyzes traffic conditions during the weekday AM and PM peak hours for the
following scenarios:
• 2022 Existing Traffic Conditions
• 2023 No-Build Traffic Conditions
• 2023 Build Traffic Conditions
2. Existing Traffic Conditions
The study area for the TIA was determined through coordination with the WMPO and NCDOT
and consists of the following existing intersections:
• US 17 and Mendenhall Drive / Marsh Oaks Drive
• US 17 and Hays Lane / Commercial Driveway
• Marsh Oaks Drive and Amberleigh Shores Driveway
Marsh Oaks Development | E-2
Existing peak hour traffic volumes were determined based on a combination of previously
conducted turning movement counts and newly collected traffic counts. Peak hour turning
movement counts were conducted at the following study intersections during the weekday AM
and PM peak hours at the dates listed below:
• US 17 (Market Street) and Hays Lane – March 25th, 2021
• US 17 (Market Street) and Mendenhall Drive / Marsh Oaks Drive – March 25th, 2021
• Marsh Oaks Drive and Amberleigh Shores Driveway – February 8th, 2022
Through coordination with the WMPO and NCDOT, a COVID-19 adjustment factor of 1.26
during the weekday AM peak hour and 1.16 during the weekday PM peak hour was applied to
all turning movement counts collected in 2021 per the methodology in the Primrose School of
Mayfaire development TIA. These previously collected counts were projected to the year 2022
using a compounded annual growth rate of 2%. It should be noted that this methodology was
approved during scoping, by the WMPO and NCDOT.
3. Site Trip Generation
The proposed development is assumed to consist of a maximum of 10,200 square feet (s.f) of
medical-dental office, 6,300 s.f. of strip retail plaza, and 2,400 s.f. of high-turnover sit-down
restaurant. Average weekday daily, AM peak hour, and PM peak hour trips for the proposed
development were estimated using methodology contained within the ITE Trip Generation
Manual, 10th Edition. Table E-1, on the following page, provides a summary of the trip
generation potential for the site.
Marsh Oaks Development | E-3
Table E-1: Site Trip Generation
Land Use
(ITE Code) Intensity
Daily
Traffic
(vpd)
Weekday
AM Peak
Hour Trips
(vph)
Weekday
PM Peak
Hour Trips
(vph)
Enter Exit Enter Exit
Medical Office
(720) 10,200 s.f. 360 22 6 10 25
Shopping Center*
(822) 6,300 s.f. 500 13 8 28 28
High-Turnover Sit-Down
(932) 2,400 s.f. 300 19 15 22 20
Total Trips 1,160 54 29 60 73
Pass-By Trips: Shopping Center
(34% PM) -- -- -10 -10
Pass-By Trips: High-Turnover (Sit-Down) Restaurant
(43% PM) -- -- -9 -9
Total Primary Trips 54 29 41 54
*ITE 11th Edition utilized due to more accuracy with the square footage below 40 ksf for LUC 820.
4. Future Traffic Conditions
Through coordination with the WMPO and NCDOT, it was determined that an annual growth
rate of 2% would be used to generate 2023 projected weekday AM and PM peak hour traffic
volumes. The following adjacent developments were identified to be considered under future
conditions:
• Primrose School of Mayfaire (Primrose Daycare)
5. Capacity Analysis Summary
The analysis considered weekday AM and PM peak hour traffic for 2022 existing, 2023 no-build,
and 2023 build conditions. Refer to Section 7 of the TIA for the capacity analysis summary
performed at each study intersection.
6. Recommendations
Based on the findings of this study, specific geometric and traffic control improvements have
been identified at study intersections. The improvements are summarized on the following page
and are illustrated in Figure E-1.
Marsh Oaks Development | E-4
Improvements by Others
US 17 (Market Street) and Mendenhall Drive / Marsh Oaks Drive
• Extension of the southbound left turn lane on US 17 to 400 feet of storage with
an appropriate deceleration and taper length.
US 17 (Market Street) and Primrose Site Access 1
• Provide a northbound right turn lane with 75 feet of storage and appropriate
deceleration and taper.
• Construct the site access as right in/right out only, with one ingress lane and one
egress lane.
• Provide stop control for the westbound approach and 100 feet of internal protected
stem.
Marsh Oaks Drive and Primrose Site Access 2
• Construct the site access with one ingress and one egress lane.
• Provide stop control for the southbound approach and 100 feet of internal protected
stem.
Improvements by Developer
Due to committed improvements by other developments and low impacts to the study
intersections, no additional improvements are recommended by the developer.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
Signalized Intersection
Unsignalized Intersection
LEGEND
Existing Lane
X'Storage (In Feet)
Improvement by Others
Figure E-1
Recommended Lane
Configurations
Right-in/right-out Intersection
E-5
N
Mendenhall
Drive
17
Marsh Oaks
Drive
17
Hays
Lane
Commercial
Driveway
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Primrose
Site Drive 1 SITE
40
0
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20
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150'
150'
75'
175'300'300'40
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40
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15
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67
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87
5
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75
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Marsh Oaks Development | i
TABLE OF CONTENTS
1. INTRODUCTION .................................................................................. 1
1.1. Site Location and Study Area ....................................................... 1
1.2. Proposed Land Use and Site Access .............................................. 2
1.3. Adjacent Land Uses .................................................................... 2
1.4. Existing Roadways ..................................................................... 2
2. 2022 EXISTING PEAK HOUR CONDITIONS .......................................... 7
2.1. 2022 Existing Peak Hour Traffic Volumes ...................................... 7
2.2. Analysis of 2022 Existing Peak Hour Traffic Conditions .................... 7
3. 2023 NO-BUILD PEAK HOUR CONDITIONS ......................................... 9
3.1. Ambient Traffic Growth ............................................................... 9
3.2. Adjacent Development Traffic ...................................................... 9
3.3. Future Roadway Improvements ................................................. 10
3.4. 2023 No-Build Peak Hour Traffic Volumes ................................... 10
3.5. Analysis of 2023 No-Build Peak Hour Traffic Conditions ................. 10
4. SITE TRIP GENERATION AND DISTRIBUTION ................................... 14
4.1. Trip Generation ........................................................................ 14
4.2. Site Trip Distribution and Assignment ......................................... 15
5. 2023 BUILD TRAFFIC CONDITIONS .................................................. 21
5.1. 2023 Build Peak Hour Traffic Volumes ........................................ 21
5.2. Analysis of 2023 Build Peak Hour Traffic Conditions ...................... 21
6. TRAFFIC ANALYSIS PROCEDURE ....................................................... 23
6.1. Adjustments to Analysis Guidelines ............................................ 24
7. CAPACITY ANALYSIS ........................................................................ 25
7.1. US 17 [NB-SB] and Mendenhall Drive [EB] / Marsh Oaks Drive
[WB] ...................................................................................... 25
7.2. US 17 [NB-SB] and Hays Lane [EB] / Commercial Driveway
[WB] ...................................................................................... 29
7.3. Marsh Oaks Drive and Amberleigh Shores Driveway / Primrose
Site Drive 2 ............................................................................. 31
Marsh Oaks Development | ii
7.4. US 17 and Primrose Site Drive 1 ................................................ 33
8. CONCLUSIONS .................................................................................. 34
9. RECOMMENDATIONS ......................................................................... 35
LIST OF FIGURES
Figure 1 – Site Location Map ............................................................... 4
Figure 2 – Preliminary Site Plan ........................................................... 5
Figure 3 – Existing Lane Configurations ................................................ 6
Figure 4 – 2022 Existing Peak Hour Traffic............................................ 8
Figure 5 – 2023 Projected Peak Hour Traffic ........................................ 11
Figure 6 – Adjacent Development Trips ............................................... 12
Figure 7 – 2023 No-Build Peak Hour Traffic.......................................... 13
Figure 8 – Site Trip Distribution .......................................................... 16
Figure 9 – Site Trip Assignment.......................................................... 17
Figure 10 – Pass-By Site Trip Distribution ............................................ 18
Figure 11 – Pass-by Site Trip Assignment ............................................ 19
Figure 12 – Total Site Trip Assignment ................................................ 20
Figure 13 – 2023 Build Peak Hour Traffic ............................................. 22
Figure 14 – Recommended Lane Configurations ................................... 36
Marsh Oaks Development | iii
LIST OF TABLES
Table 1: Existing Roadway Inventory .................................................... 3
Table 2: Adjacent Development Information .......................................... 9
Table 3: Trip Generation Summary ..................................................... 14
Table 4: Highway Capacity Manual – Levels-of-Service and Delay ........... 23
Table 5: Analysis Summary of US 17 and Mendenhall Drive / Marsh Oaks
Drive ...................................................................................... 25
Table 6: Analysis Summary of US 17 and Hays Lane / Commercial Driveway
............................................................................................. 29
Table 7: Analysis Summary of Marsh Oaks Drive and Amberleigh Shores
Driveway / Primrose Site Drive 2 ............................................... 31
Table 8: Analysis Summary of US 17 & Primrose Site Drive 1 ................ 33
Marsh Oaks Development | iv
TECHNICAL APPENDIX
Appendix A: Scoping Documentation
Appendix B: Traffic Counts
Appendix C: Signal Information
Appendix D: Adjacent Development Information
Appendix E: Capacity Calculations – US 17 & Mendenhall Drive / Marsh
Oaks Drive
Appendix F: Capacity Calculations – US 17 & Hays Lane / Commercial
Driveway
Appendix G: Capacity Calculations – Marsh Oaks & Amberleigh Shores
Driveway / Primrose Site Drive 2
Appendix H: Capacity Calculations – US 17 & Primrose Site Drive 1
Appendix I: SimTraffic Queueing Reports
Appendix J: Turn Lane Warrants
TRAFFIC IMPACT ANALYSIS
MARSH OAKS DEVELOPMENT
NEW HANOVER COUNTY, NORTH CAROLINA
1. INTRODUCTION
The contents of this report present the findings of the Traffic Impact Analysis (TIA) conducted
for the proposed Marsh Oaks development to be located along US 17 (Market Street) and
Marsh Oaks Drive in New Hanover County, North Carolina. The purpose of this study is to
determine the potential impacts to the surrounding transportation system created by traffic
generated by the proposed development, as well as recommend improvements to mitigate
the impacts.
The proposed development, anticipated to be completed in 2023, is assumed to consist of the
following uses:
• 10,200 square feet (s.f.) of medical-dental office
• 6,300 s.f. of strip retail plaza
• 2,400 s.f. of high-turnover sit-down restaurant
The study analyzes traffic conditions during the weekday AM and PM peak hours for the
following scenarios:
• 2022 Existing Traffic Conditions
• 2023 No-Build Traffic Conditions
• 2023 Build Traffic Conditions
1.1. Site Location and Study Area
The development is proposed to be located along US 17 and Marsh Oaks Drive in New
Hanover County, North Carolina. Refer to Figure 1 for the site location map.
The study area for the TIA was determined through coordination with the Wilmington Urban
Area and Metropolitan Planning Organization (WMPO) and the North Carolina Department
of Transportation (NCDOT) and consists of the following existing intersections:
Marsh Oaks Development | 2
• US 17 and Mendenhall Drive / Marsh Oaks Drive
• US 17 and Hays Lane / Commercial Driveway
• Marsh Oaks Drive and Amberleigh Shores Driveway
Refer to Appendix A for the approved scoping documentation.
1.2. Proposed Land Use and Site Access
The site is expected to be located along Marsh Oaks Drive. The proposed development,
anticipated to be completed in 2023, is assumed to consist of the following uses:
• 10,200 s.f. of medical-dental office
• 6,300 s.f. of strip retail plaza
• 2,400 s.f. of high-turnover sit-down restaurant
Site access is proposed via one (1) full movement driveway along Marsh Oaks Drive as well
as one (1) right-in/right-out (RIRO) driveway on US 17 (Market Street). The full movement
driveway on Marsh Oaks Drive is proposed to be aligned with the Amberleigh Shores
Driveway. It should be noted that these driveway connections are expected to be constructed
by the Primrose School of Mayfaire development. Refer to Section 3.2 of this report for
adjacent development information. Refer to Figure 2 for a copy of the preliminary site plan.
1.3. Adjacent Land Uses
The proposed development is located in an area consisting primarily of residential and
commercial development.
1.4. Existing Roadways
Existing lane configurations (number of traffic lanes on each intersection approach), lane
widths, storage capacities, and other intersection and roadway information within the study
area are shown in Figure 3. Table 1, on the following page, provides a summary of this
information, as well.
Marsh Oaks Development | 3
Table 1: Existing Roadway Inventory
Road Name Route
Number
Typical
Cross
Section
Speed Limit Maintained
By
2019 AADT
(vpd)
Market Street US 17 4-lane
divided 45 mph NCDOT 44,500
Mendenhall
Drive SR 2290 2-lane
divided
25 mph
(assumed) NCDOT 1,630*
Marsh Oaks
Drive SR 2734 2-lane
undivided 25 mph NCDOT 5,570*
Hays Lane N/A 2-lane
divided
25 mph
(assumed) N/A 9,290*
*ADT based on the traffic counts from 2022 and assuming the weekday PM peak hour volume is 10%
of the average daily traffic.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
LEGEND
Proposed Site Location
Study Intersection
Proposed Site Access
Study Area
Site Location Map
Figure 1
SR
2
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9
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SR 2734 (Marsh Oaks Drive)
H
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Primrose Daycare Site Access
4
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
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LEGEND
Signalized Intersection
Unsignalized Intersection
Existing Lane
X'Storage (In Feet)
SPEEDLIMITXX Posted Speed Limit
20
0
'
20
0
'
SPEEDLIMIT 45
SPEEDLIMIT 25
2022 Existing
Lane Configurations
Figure 3
150'
150'
75'
175'300'300'40
0
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40
0
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15
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67
5
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87
5
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6
Marsh Oaks Development | 7
2. 2022 EXISTING PEAK HOUR CONDITIONS
2.1. 2022 Existing Peak Hour Traffic Volumes
Existing peak hour traffic volumes were determined based on a combination of previously
conducted turning movement counts and newly collected traffic counts. Peak hour turning
movement counts were conducted at the following study intersections during the weekday
AM and PM peak hours at the dates listed below:
• US 17 (Market Street) and Hays Lane – March 25th, 2021
• US 17 (Market Street) and Mendenhall Drive / Marsh Oaks Drive – March 25th, 2021
• Marsh Oaks Drive and Amberleigh Shores Driveway – February 8th, 2022
Through coordination with the WMPO and NCDOT, a COVID-19 adjustment factor of 1.26
during the weekday AM peak hour and 1.16 during the weekday PM peak hour was applied
to all turning movement counts collected in 2021 per the methodology in the Primrose School
of Mayfaire development TIA. These previously collected counts were projected to the year
2022 using a compounded annual growth rate of 2%. It should be noted that this methodology
was approved during scoping, by the WMPO and NCDOT.
Refer to Figure 4 for 2022 existing weekday AM and PM peak hour traffic volumes. A copy
of the count data is located in Appendix B of this report.
2.2. Analysis of 2022 Existing Peak Hour Traffic Conditions
The 2022 existing weekday AM and PM peak hour traffic volumes were analyzed to
determine the current levels of service at the study intersections under existing roadway
conditions. Signal information was obtained from NCDOT and is included in Appendix C.
The results of the analysis are presented in Section 7 of this report.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
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2022 Existing
Peak Hour Traffic
Figure 4
173/1481/2136/107
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31/341/234/50
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Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak
Hour TrafficX / Y
LEGEND
163/1314/10
65
/
9
9
5/
1
6
3/1
79/17014/41
8
Marsh Oaks Development | 9
3. 2023 NO-BUILD PEAK HOUR CONDITIONS
In order to account for growth of traffic and subsequent traffic conditions at a future year, no-
build traffic projections are needed. No-build traffic is the component of traffic due to the
growth of the community and surrounding area that is anticipated to occur regardless of
whether or not the proposed development is constructed. No-build traffic is comprised of
existing traffic growth within the study area and additional traffic created as a result of
adjacent approved developments.
3.1. Ambient Traffic Growth
Through coordination with the WMPO and NCDOT, it was determined that an annual
growth rate of 2% would be used to generate 2023 projected weekday AM and PM peak hour
traffic volumes. Refer to Figure 5 for 2023 projected peak hour traffic.
3.2. Adjacent Development Traffic
Through coordination with the WMPO and NCDOT, the following adjacent development
was identified to be included as an approved adjacent development in this study:
• Primrose School of Mayfaire (Primrose Daycare)
Table 2 provides a summary of the adjacent development.
Table 2: Adjacent Development Information
Development
Name Location Build-
Out Year
Land Use /
Intensity
TIA
Performed
Primrose School
of Mayfaire 7984 Market Street 2022 191 Student Day-Care
Center
2021
by RKA
It should be noted that the adjacent development was approved, during scoping, by the
WMPO and NCDOT. Adjacent development trips are shown in Figure 6. Adjacent
development information can be found in Appendix D.
Marsh Oaks Development | 10
3.3. Future Roadway Improvements
Based on coordination with the NCDOT and the WMPO, it was determined that the roadway
improvements associated with the Primrose School of Mayfaire development should be
considered in this study.
3.4. 2023 No-Build Peak Hour Traffic Volumes
The 2023 no-build traffic volumes were determined by projecting the 2022 existing peak hour
traffic to the year 2023, and adding the adjacent development trips. Refer to Figure 7 for an
illustration of the 2023 no-build peak hour traffic volumes at the study intersections.
3.5. Analysis of 2023 No-Build Peak Hour Traffic Conditions
The 2023 no-build AM and PM peak hour traffic volumes at the study intersections were
analyzed with future geometric roadway conditions and traffic control. The analysis results
are presented in Section 7 of this report.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
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Mendenhall
Drive
17
17
Marsh Oaks
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Hays
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Commercial
Driveway
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2023 Projected
Peak Hour Traffic
Figure 5
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Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak
Hour TrafficX / Y
LEGEND
11
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
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Primrose
Site Drive 1
Peak Hour Approved
Development Trips
Figure 6
Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak Hour
Approved Development TripsX / Y
LEGEND
32/36
36
/
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Right-In/Right-Out Intersection
12
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
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Marsh Oaks
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Hays
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Commercial
Driveway
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Primrose
Site Drive 1
2023 No-Build
Peak Hour Traffic
Figure 7
Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak Hour
TrafficX / Y
LEGEND
Right-In/Right-Out Intersection
176/1511/2171/145
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Marsh Oaks Development | 14
4. SITE TRIP GENERATION AND DISTRIBUTION
4.1. Trip Generation
The proposed development is assumed to consist of 10,200 s.f. of medical-dental office space,
6,300 s.f. of strip retail plaza, and a 2,400 s.f. high-turnover sit-down restaurant. Average
weekday daily, AM peak hour, and PM peak hour trips for the proposed development were
estimated using methodology contained within the ITE Trip Generation Manual, 10th Edition.
Table 3 provides a summary of the trip generation potential for the site.
Table 3: Trip Generation Summary
Land Use
(ITE Code) Intensity
Daily
Traffic
(vpd)
Weekday
AM Peak
Hour Trips
(vph)
Weekday
PM Peak
Hour Trips
(vph)
Enter Exit Enter Exit
Medical Office
(720) 10,200 s.f. 360 22 6 10 25
Strip Retail*
(822) 6,300 s.f. 500 13 8 28 28
High-Turnover Sit-Down
(932) 2,400 s.f. 300 19 15 22 20
Total Trips 1,160 54 29 60 73
Pass-By Trips: Shopping Center
(34% PM) -- -- -10 -10
Pass-By Trips: High-Turnover (Sit-Down) Restaurant
(43% PM) -- -- -9 -9
Total Primary Trips 54 29 41 54
*ITE 11th Edition utilized due to more accuracy with the square footage below 40 ksf for LUC 820.
It is estimated that the proposed development will generate approximately 1,160 total site
trips on the roadway network during a typical 24-hour weekday period. Of the daily traffic
volume, it is anticipated that 83 trips (54 entering and 29 exiting) will occur during the
weekday AM peak hour and 133 (60 entering and 73 exiting) will occur during the weekday
PM peak hour. It should be noted that ITE 11th Edition was utilized to estimate the trip
generation for the shopping center due to its increased accuracy for smaller-densities
compared to the 10th Edition.
Marsh Oaks Development | 15
Pass-by trips were also taken into consideration in this study. Pass-by trips are made by the
traffic already using the adjacent roadway, entering the site as an intermediate stop on their
way to another destination. Pass-by percentages are applied to site trips after adjustments for
internal capture. Pass-by trips are expected to account for approximately 38 trips (19 entering
and 19 exiting) during the weekday PM peak hour. It should be noted that the pass-by trips
were balanced, as it is likely that these trips would enter and exit in the same hour.
The total primary site trips are the calculated site trips after the reduction for internal capture
and pass-by trips. Primary site trips are expected to generate approximately 83 trips (54
entering and 29 exiting) during the weekday AM peak hour and 95 trips (41 entering and 54
exiting) during the weekday PM peak hour.
4.2. Site Trip Distribution and Assignment
Trip distribution percentages used in assigning site traffic for this development were
estimated based on a combination of existing traffic patterns, population centers adjacent to
the study area, and engineering judgment.
It is estimated that the site trips will be regionally distributed as follows:
• 45% to/from the north via US 17
• 45% to/from the south via US 17
• 5% to/from the east via Marsh Oaks Drive
• 5% to/from the south via Amberleigh Shores Driveway
The site trip distribution is shown in Figure 8. Refer to Figure 9 for the site trip assignment.
The pass-by site trips were distributed based on existing traffic patterns with consideration
given to the proposed driveway access and site layout. Refer to Figure 10 for the pass-by site
trip distribution. Pass-by site trips are shown in Figure 11.
The total site trips were determined by adding the primary site trips and the pass-by site trips.
Refer to Figure 12 for the total peak hour site trips at the study intersections.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
45%
XX%
Entering Trip Distribution
Exiting Trip Distribution
Regional Trip Distribution
Signalized Intersection
Unsignalized Intersection
Right-In/Right-Out Intersection
X%
(Y%)
45
%
Site Trip Distribution
LEGEND
Figure 8
5%
5%
45%
45
%
35
%
10
%
25
%
20
%
55%
5%
5%
(6
0
%
)
(5
%
)
(5
%
)
(45%)
(30%)
(1
5
%
)
35
%
(4
5
%
)
(15%)
16
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
Site Trip Assignment
Figure 9
Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak Hour
Site TripsX / Y
LEGEND
Right-In/Right-Out Intersection
23
/
1
8
23
/
1
8
18
/
1
4
5/
4
14
/
1
0
11
/
9
29/23
3/
2
3/2
17
/
3
2
1/
3
1/
3
13/24
10/16
4/
8
19
/
1
4
14
/
2
4
4/8
17
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
Pass-By Site Trip
Distribution
Figure 10
Signalized Intersection
Unsignalized Intersection
Weekday PM Pass-By
Trip DistributionX%
Right-In/Right-Out Intersection
LEGEND
-5
0
%
40
%
10
%
-2
5
%
25
%
65%
70
%
50%
30%
-3
0
%
3
5
%
20%
18
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
Pass-By Site Trip
Assignment
Figure 11
-9 7 2
-55
12
13
9
6
-6 7
4
Signalized Intersection
Unsignalized Intersection
Weekday PM Peak Hour
Site TripsX
LEGEND
Right-In/Right-Out Intersection
19
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
Total Site Trip
Assignment
Figure 12
Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak Hour
Site TripsX / Y
LEGEND
Right-In/Right-Out Intersection
4/12
14
/
5
11
/
1
4
3/
2
0/
-
9
18
/
2
1
5/
6
17
/
4
5
1/
3
1/
3
3/2
29/35
23
/
1
8
10/22
4/
2
19
/
2
1
13/33
23
/
1
8
14
/
2
4
20
Marsh Oaks Development | 21
5. 2023 BUILD TRAFFIC CONDITIONS
5.1. 2023 Build Peak Hour Traffic Volumes
To estimate traffic conditions with the site fully built-out, the total site trips were added to the
2023 no-build traffic volumes to determine the 2023 build traffic volumes. Refer to Figure 13
for an illustration of the 2023 build peak hour traffic volumes with the proposed site fully
developed.
5.2. Analysis of 2023 Build Peak Hour Traffic Conditions
Study intersections were analyzed with the 2023 build traffic volumes using the same
methodology previously discussed for existing and no-build traffic conditions. Intersections
were analyzed with improvements necessary to accommodate future traffic volumes. The
results of the capacity analysis for each intersection are presented in Section 7 of this report.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
N
Mendenhall
Drive
17
17
Marsh Oaks
Drive
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
2023 Build
Peak Hour Traffic
Signalized Intersection
Unsignalized Intersection
Weekday AM / PM Peak
Hour TrafficX / Y
LEGEND
Right-In/Right-Out Intersection
22
Figure 13
180/1631/2184/178
36
/
5
4
18
3
5
/
2
1
0
1
10
9
/
1
3
3
66
/
1
0
1
3/
2
5/
1
6
32/351/235/51
11
8
/
2
2
2
20
9
6
/
1
7
4
7
60
/
1
4
23
/
6
7
14/374/815/54
16
4
/
2
5
5
19
6
2
/
2
0
1
6
47
/
5
143/2825/794/173
32
/
2
2
18
9
9
/
2
0
4
3
15
8
/
2
3
8
37
/
1
4
49
/
8
1
1/
3
7/
1
1
10/9166/1344/10
3/165/6781/17314/42
21
2
6
/
2
3
1
7
42/58
20
2
9
/
2
2
6
0
55
/
5
3
Marsh Oaks Development | 23
6. TRAFFIC ANALYSIS PROCEDURE
Study intersections were analyzed using the methodology outlined in the Highway Capacity
Manual (HCM), 6th Edition published by the Transportation Research Board. Capacity and
level of service are the design criteria for this traffic study. A computer software package,
Synchro (Version 10.3), was used to complete the analyses for most of the study area
intersections. Please note that the unsignalized capacity analysis does not provide an overall
level of service for an intersection; only delay for an approach with a conflicting movement.
The HCM defines capacity as “the maximum hourly rate at which persons or vehicles can
reasonably be expected to traverse a point or uniform section of a lane or roadway during a
given time period under prevailing roadway, traffic, and control conditions.” Level of service
(LOS) is a term used to represent different driving conditions, and is defined as a “qualitative
measure describing operational conditions within a traffic stream, and their perception by
motorists and/or passengers.” Level of service varies from Level “A” representing free flow,
to Level “F” where breakdown conditions are evident. Refer to Table 4 for HCM levels of
service and related average control delay per vehicle for both signalized and unsignalized
intersections. Control delay as defined by the HCM includes “initial deceleration delay, queue
move-up time, stopped delay, and final acceleration delay”. An average control delay of 50
seconds at a signalized intersection results in LOS “D” operation at the intersection.
Table 4: Highway Capacity Manual – Levels-of-Service and Delay
UNSIGNALIZED INTERSECTION SIGNALIZED INTERSECTION
LEVEL
OF
SERVICE
AVERAGE
CONTROL DELAY
PER VEHICLE
(SECONDS)
LEVEL OF
SERVICE
AVERAGE
CONTROL DELAY
PER VEHICLE
(SECONDS)
A
B
C
D
E
F
0-10
10-15
15-25
25-35
35-50
>50
A
B
C
D
E
F
0-10
10-20
20-35
35-55
55-80
>80
Marsh Oaks Development | 24
6.1. Adjustments to Analysis Guidelines
Capacity analysis at all study intersections was completed according to the NCDOT
Congestions Management Guidelines. A summary of adjustments to these guidelines made
throughout the analysis is provided below:
• The existing intersection of Marsh Oaks Drive and Amberleigh Shores Driveway was
shown during data collection to facilitate u-turn movements for vehicles traveling
eastbound on Marsh Oaks Drive due to the presence of a wide median on the
eastbound approach. Due to limitations with HCM 6th TWSC reporting, a level-of-
service and delay could not be computed for the eastbound approach with the
presence of these u-turn movements. As a result, these u-turn volumes were removed
from the analysis under 2022 existing conditions, and added to the eastbound left-turn
movement under 2023 no-build and 2023 build traffic conditions once the southbound
approach has been constructed. This adjustment was done in order to report a delay
for the eastbound approach under 2023 no-build and 2023 build traffic conditions.
Marsh Oaks Development | 25
7. CAPACITY ANALYSIS
7.1. US 17 [NB-SB] and Mendenhall Drive [EB] / Marsh Oaks Drive [WB]
The existing signalized intersection of US 17 and Mendenhall Drive / Marsh Oaks Drive was
analyzed under 2022 existing, 2023 no-build, and 2023 build traffic conditions with lane
configurations and traffic control shown in Table 5. Refer to Table 5 for a summary of the
analysis results. Refer to Appendix E for the Synchro capacity analysis reports. SimTraffic
Queueing reports can be found in Appendix I.
Table 5: Analysis Summary of US 17 and Mendenhall Drive / Marsh Oaks
Drive
ANALYSIS
SCENARIO
LANE
GROUP
Existing
Storage
(ft)
Weekday AM Peak Hour Weekday PM Peak Hour
Queue
95th / Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
Queue 95th /
Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
2022
Existing
Conditions
EBL/T
EBR
--
150
68 / 90
59 / 110
E
D
58
45 D (51)
C
(23)
78 / 121
82 / 119
E
D
63
48 D (54)
C
(34)
WBL/T
WBR
--
150
224 / 296
265 / 242
F
F
83
82 F (82) 188 / 367
238 / 250
F
F
83
86 F (85)
NBL
NBT
NBR
500
--
875
33 / 73
1193 / 514
83 / 77
B
C
B
17
27
12
C (26)
57 / 391
1464 / 830
93 / 90
C
D
B
27
43
13
D (41)
SBU/L
SBT/TR
200
--
130 / 219
122 / 340
E
A
69
6 A (10) 194 / 300
383 / 562
E
B
65
16 B (20)
2023
No-Build
Conditions
EBL/T
EBR
--
150
68 / 92
54 / 84
D
D
54
39 D (46)
D
(39)
80 / 112
79 / 110
E
D
64
43 D (52)
E
(57)
WBL/T
WBR
--
150
267 / 323
258 / 250
F
E
84
69 E (77) 276 / 306
244 / 248
F
E
98
78 F (88)
NBL
NBT
NBR
500
--
875
81 / 294
1319 / 748
89 / 108
F
E
B
82
57
17
E (55)
107 / 599
1548 / 1090
95 / 975
F
F
B
81
86
15
F (82)
SBU/L
SBT/TR
400
--
216 / 288
1320 / 358
F
B
89
11 B (17) 276 / 334
389 / 450
F
C
93
20 C (28)
2023
No-Build
Conditions
(Field)
EBL/T
EBR
--
150
68 / 96
57 / 107
D
D
54
41 D (47)
C
(30)
80 / 104
83 / 123
E
D
64
46 D (54)
D
(48)
WBL/T
WBR
--
150
267 / 300
258 / 250
F
E
84
69 E (77) 276 / 332
244 / 247
F
E
98
78 F (88)
NBL
NBT
NBR
500
--
875
35 / 283
1319 / 650
89 / 89
B
D
B
18
39
15
D (38)
57 / 599
1548 / 1092
95 / 814
C
E
B
27
72
14
E (68)
SBU/L
SBT/TR
400
--
171 / 296
1266 / 375
E
A
76
8 B (14) 230 / 328
367 / 425
E
B
70
18 C (23)
Improvements and/or revised lane configurations by others are shown underlined.
Marsh Oaks Development | 26
Table 5: Analysis Summary of US 17 and Mendenhall Drive / Marsh Oaks
Drive (cont.)
ANALYSIS
SCENARIO LANE
GROUP
Existing
Storage
(ft)
Weekday AM Peak Hour Weekday PM Peak Hour
Queue
95th / Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
Queue 95th
/ Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
2023
Build
Conditions
EBL/T
EBR
--
150
67 / 83
53 / 91
D
D
52
37 D (45)
D
(48)
81 / 102
79 / 102
E
D
64
43 D (52)
E
(67)
WBL/T
WBR
--
150
283 / 328
259 / 249
F
E
83
67 E (75) 365 / 350
263 / 250
F
E
113
76 F (95)
NBL
NBT
NBR
500
--
875
81 / 498
1337 / 894
97 / 290
F
E
B
82
77
19
E (74)
107 / 600
1554 / 1097
105 / 975
F
F
B
81
106
16
F (100)
SBU/L
SBT/TR
400
--
289 / 329
1318 / 386
F
B
85
12 B (19) 312 / 380
357 / 462
F
C
103
23 C (31)
2023
Build
Conditions
(Field)
EBL/T
EBR
--
150
67 / 90
55 / 92
D
D
52
40 D (46)
C
(35)
81 / 71
83 / 132
E
D
64
46 D (54)
E
(59)
WBL/T
WBR
--
150
283 / 314
259 / 250
F
E
83
67 E (75) 365 / 344
263 / 250
F
E
113
76 F (95)
NBL
NBT
NBR
500
--
875
36 / 285
1337 / 776
97 / 100
B
D
B
18
50
17
D (48)
57 / 600
1554 / 1087
105 / 975
C
F
B
27
93
15
F (87)
SBU/L
SBT/TR
400
--
194 / 290
1264 / 347
E
A
75
10 B (16) 259 / 327
351 / 463
E
B
75
20 C (26)
Improvements and/or revised lane configurations by others are shown underlined.
Capacity analysis indicates that the intersection of US 17 and Mendenhall Drive / Marsh Oaks
Drive is expected to operate at an overall LOS D or better during the weekday AM and PM
peak hours under existing and all future traffic conditions, with the exception of the weekday
PM peak hour under 2023 no-build and 2023 build traffic conditions which is expected to
operate at an overall LOS E. Approach delays are expected to operate at LOS E or better except
for the westbound approach during the weekday AM and PM peak hour under 2022 existing
conditions, and the westbound and northbound approaches during the weekday PM peak
hours under 2023 no-build and 2023 build traffic conditions. Between 2023 no-build and 2023
build traffic conditions the northbound approach is expected to experience an increase in
delay of greater than 25% during the weekday AM peak hour. While Congestion Management
guidelines call for mitigation if an approach or overall level-of-service degrades by one level,
operates at LOS F, or experiences an increase of delay by greater than 25%, the proposed
development trips are expected to account for less than 2% of the overall traffic at this
intersection during the weekday AM and PM peak hours. Additionally, the eastbound and
northbound approaches are expected to operate at failing levels-of-service whether or not the
proposed development is constructed.
Marsh Oaks Development | 27
Geometric intersection improvements were explored; however, in order to allow for dual left-
turn lanes along US 17, an additional receiving lane would need to be construction on the
minor-street approaches of Mendenhall Drive and Marsh Oaks Drive. Due to right-of-way
constraints on the minor-streets, additional lanes are not recommended at this intersection. It
should be noted that extension of the existing southbound left-turn lane by 200 feet is an
expected improvement to be built by others prior to the buildout of the proposed
development.
Based on the queueing analysis results, queueing delays can be expected; however, these
delays are present under 2022 existing and 2023 no-build traffic conditions. When comparing
2023 no-build queues to 2023 build queues the southbound left-turn movement is expected to
increase by 71 feet or less (approximately 3 vehicles), and the westbound left-through
movement is expected to increase by 89 feet or less (approximately 4 vehicles). Due to the
heavy mainline volumes on US 17, turn lanes on the northbound and southbound approaches
are expected to be blocked by vehicles queued in the adjacent through lanes during the
weekday AM and PM peak hours. Westbound queues at this intersection are not expected to
block the proposed site driveway along Marsh Oaks Road.
In the field, the signal currently operates with ‘permitted-protected’ phasing for the major-
street left-turn movements despite the high volume of through traffic along US 17. Allowing
this phasing decreases delays and queueing at the intersection which improves lane group,
approach, and overall LOS at the intersection. No-build and build analysis with field
conditions shows the conditions where the northbound and southbound left-turn movements
are modeled with this existing ‘permitted-protected’ phasing. Capacity analysis of 2023 no-
build and 2023 build traffic conditions with this phasing indicates the intersection is expected
to operate at an overall LOS D or better during the weekday AM and PM peak hours, with
the exception of the weekday PM peak hour under 2023 build traffic conditions (LOS E).
Based on the queueing analysis results, queues are expected to be similar or better than those
reported under the protected-only analysis scenarios.
Marsh Oaks Development | 28
It should be noted that State Transportation Improvement Project (STIP) U-4751 is expected
to construct the Military Cutoff Road Extension from US 17 to the future Hampstead Bypass.
When comparing the 2035 forecast volumes for Scenario 1 (existing conditions) and Scenario
10, it was determined that through volumes along US 17 are expected to experience
approximately an 11% reduction in traffic as a result of this project. It is likely that operations
at this intersection will improve in the future as this planned improvement is constructed.
Due to the traffic operations remaining consistent between no-build and build traffic
conditions, and the lack of feasible geometric improvements to improve operations of the
overall intersection, no improvements are being recommended.
Marsh Oaks Development | 29
7.2. US 17 [NB-SB] and Hays Lane [EB] / Commercial Driveway [WB]
The existing signalized intersection of US 17 and Hays Lane / Commercial Driveway was
analyzed under 2022 existing, 2023 no-build, and 2023 build traffic conditions with lane
configurations and traffic control shown in Table 6. Refer to Table 6 for a summary of the
analysis results. Refer to Appendix F for the Synchro capacity analysis reports. SimTraffic
Queueing reports can be found in Appendix I.
Table 6: Analysis Summary of US 17 and Hays Lane / Commercial
Driveway
ANALYSIS
SCENARIO
LANE
GROUP
Existing
Storage
(ft)
Weekday AM Peak Hour Weekday PM Peak Hour
Queue
95th / Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
Queue
95th / Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
2022
Existing
Conditions
EBL
EBT
EBR
175
--
300
119 / 177
23 / 42
84 / 124
E
E
E
79
73
61
E (72)
C
(31)
205 / 251
27 / 42
125 / 184
E
E
D
79
72
52
E (69)
D
(42)
WBL
WBT/R
75
--
39 / 45
50 / 65
E
E
56
79 E (69) 89 / 109
95 / 105
D
F
51
89 E (68)
NBL
NBT/TR
400
--
107 / 213
1325 / 839
E
C
64
21 C (25) 176 / 242
1383 / 574
E
D
59
41 C (29)
SBU/L
SBT
SBR
150
--
675
150 / 250
1397 / 636
31 / 59
F
C
A
83
32
4
C (33)
144 / 250
1195 / 825
133 / 252
F
D
B
81
53
10
D (50)
2023
No-Build
Conditions
EBL
EBT
EBR
175
--
300
120 / 175
23 / 43
85 / 131
E
E
E
79
73
61
E (72)
D
(36)
209 / 246
27 / 39
127 / 172
E
E
D
79
72
52
E (69)
D
(48)
WBL
WBT/R
75
--
42 / 52
50 / 70
E
E
61
79 E (71) 100 / 102
96 / 123
D
F
54
90 E (70)
NBL
NBT/TR
400
--
91 / 222
1272 / 590
E
C
68
27 C (30) 108 / 251
1133 / 587
D
C
49
31 C (33)
SBU/L
SBT
SBR
150
--
675
151 / 250
1491 / 851
32 / 199
F
D
A
83
38
4
D (38)
144 / 250
1272 / 1020
137 / 648
F
E
B
81
63
11
E (58)
2023
Build
Conditions
EBL
EBT
EBR
175
--
300
120 / 164
23 / 29
85 / 138
E
E
E
79
73
61
E (72)
D
(38)
209 / 245
27 / 47
127 / 166
E
E
D
79
72
52
E (69)
D
(51)
WBL
WBT/R
75
--
42 / 58
50 / 74
E
E
61
79 E (71) 100 / 97
96 / 139
D
F
54
90 E (70)
NBL
NBT/TR
400
--
88 / 319
694 / 628
E
C
69
29 C (32) 106 / 159
1090 / 526
D
D
50
36 D (38)
SBU/L
SBT
SBR
150
--
675
151 / 250
1518 / 922
32 / 629
F
D
A
83
40
4
D (39)
144 / 250
1294 / 1081
137 / 775
F
E
B
81
67
11
E (61)
Capacity analysis indicates that the intersection of US 17 and Hays Lane / Commercial
driveway is expected to operate at an overall LOS D or better during the weekday AM and
PM peak hours under existing and all future traffic conditions. Additionally, all approach
levels-of-service are expected to operate at LOS E or better during the weekday AM and PM
Marsh Oaks Development | 30
peak hours under all future traffic conditions. Between 2023 no-build and 2023 build traffic
conditions the northbound approach is expected to experience a degradation in level-of-
service from LOS C to LOS D during the weekday PM peak hour. While Congestion
Management guidelines call for mitigation if an approach or overall level-of-service degrades
by one level, operates at LOS F, or experiences an increase of delay by greater than 25%, the
proposed development trips are expected to account for less than 1% of the overall traffic at
this intersection during the weekday AM and PM peak hours. Additionally, the northbound
approach is expected to operate at acceptable levels-of-service upon buildout of the proposed
development.
Based on the queueing analysis results, no significant queueing problems are expected.
Although queues are expected to exceed the existing storage lengths on several approaches,
no site traffic from the proposed development is expected to be added to the turning
movements at this intersection. Due to the traffic operations remaining consistent between
no-build and build traffic conditions, and the intersection operating at acceptable levels-of-
service, no improvements are being recommended.
Marsh Oaks Development | 31
7.3. Marsh Oaks Drive and Amberleigh Shores Driveway / Primrose Site
Drive 2
The existing unsignalized intersection of Marsh Oaks Drive and Amberleigh Shores Driveway
was analyzed under 2022 existing, 2023 no-build, and 2023 build traffic conditions with the
lane configurations and traffic control shown in Table 7. Refer to Table 7 for a summary of the
analysis results. Refer to Appendix G for the Synchro capacity analysis reports. SimTraffic
Queueing reports can be found in Appendix I.
Table 7: Analysis Summary of Marsh Oaks Drive and Amberleigh Shores
Driveway / Primrose Site Drive 2
ANALYSIS
SCENARIO
LANE
GROUP
Existing
Storage
(ft)
Weekday AM Peak Hour Weekday PM Peak Hour
Queue
95th* /
Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
Queue
95th* /
Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
2022
Existing
Conditions
EBT/R -- 0 / 0 -- -- --
N/A
0 / 0 -- -- --
N/A WBL/T -- 0 / 16 A1 71 A (7) 1 0 / 45 A1 81 A (8) 1
NBL/R -- 10 / 50 B2 112 B (11) 2 18 / 73 B2 122 B (12) 2
2023
No-Build
Conditions
EBL/T/R -- 3 / 61 A1 81 A (8) 1
N/A
3 / 66 A1 81 A (8) 1
N/A WBL/T/R -- 0 / 6 A1 71 A (7) 1 0 / 46 A1 81 A (8) 1
NBL/T/R -- 13 / 57 B2 132 B (13) 2 28 / 82 C2 152 C (15) 2
SBL/T/R -- 5 / 54 B2 102 B (03) 2 5 / 68 B2 102 B (10) 2
2023
Build
Conditions -
without LTL
EBL/T/R -- 5 / 67 A1 81 A (8) 1
N/A
5 / 85 A1 81 A (8) 1
N/A WBL/T/R -- 0 / 22 A1 71 A (7) 1 0 / 44 A1 81 A (8) 1
NBL/T/R -- 18 / 77 B2 152 B (15) 2 38 / 93 C2 192 C (19) 2
SBL/T/R -- 8 / 70 B2 102 B (10) 2 13 / 72 B2 112 B (11) 2
2023
Build
Conditions -
with LTL
EBL
EBT/R
50
--
5 / 66
0 / 0
A1
--
81
-- A (8) 1
N/A
5 / 50
0 / 0
A1
--
81
--
A (8) 1
--
N/A WBL/T/R -- 0 / 12 A1 71 A (7) 1 0 / 38 A1 81 A (8) 1
NBL/T/R -- 18 / 69 B2 152 A (15) 2 38 / 90 C2 192 C (19) 2
SBL/T/R -- 8 / 68 B2 102 A (10) 2 13 / 85 B2 112 B (11) 2
Improvements and/or revised lane configurations by others are shown underlined.
Improvements and/or revised lane configurations shown in BOLD.
*Due to limitations with HCM 6th TWSC reporting, a vehicle length of 25 feet was used to determine the 95th
percentile queue in feet.
1. Level of service for major-street left-turn movement.
2. Level of service for minor-street approach.
Capacity analysis of 2022 existing traffic conditions indicates that the major-street left-turn
movement and minor street approach are expected to operate at LOS B or better during the
weekday AM and PM peak hours.
Marsh Oaks Development | 32
Under future traffic conditions, the southbound leg of this intersections is expected to be
installed by the Primrose School of Mayfaire development. With this connection, capacity
analysis of 2023 no-build and 2023 build traffic conditions indicate that the major-street left-
turn movements and minor-street approaches are expected to operate at LOS C or better
during the weekday AM and PM peak hours.
Right and left-turn lanes were considered based on the NCDOT Policy on Street and Driveway
Access to North Carolina Highways and an exclusive 50-foot left-turn lane is warranted on the
eastbound approach. However, based on the present design of Marsh Oaks Drive (no lane
markings, 25 mph posted speed limit) and the residential nature of the roadway further east,
an exclusive left-turn lane is not recommended. Installation of an eastbound left-turn lane
would require the existing landscaped median along Marsh Oaks Drive to be removed to
provide for appropriate full-width storage and taper length. Additionally, traffic volumes are
not expected to significantly increase along Marsh Oaks Drive in the future post-buildout of
the proposed development as the majority of the land has been developed along Marsh Oaks
Drive past the proposed development.
Based on the queueing analysis results, no significant queueing problems are expected at this
intersection. Queues on all approaches are not expected to exceed 93 feet (approximately 4
vehicles) and are not expected to impact any adjacent intersections. Westbound queues from
the signalized intersection of US 17 and Mendenhall Drive and Marsh Oaks Drive are not
expected to block the proposed site driveway. Queues on the southbound approach are not
expected to exceed 75 feet (approximately 3 vehicles) without the installation of an eastbound
left-turn lane.
Marsh Oaks Development | 33
7.4. US 17 and Primrose Site Drive 1
The future right-in/right-out (RIRO) intersection of US 17 and Primrose Site Drive 1 was
analyzed under 2023 no-build and 2023 build traffic conditions with the lane configurations
and traffic control shown in Table 8. Refer to Table 8 for a summary of the analysis results.
Refer to Appendix H for the Synchro capacity analysis reports. SimTraffic Queueing reports
can be found in Appendix I.
Table 8: Analysis Summary of US 17 & Primrose Site Drive 1
ANALYSIS
SCENARIO
LANE
GROUP
Existing
Storage
(ft)
Weekday AM Peak Hour Weekday PM Peak Hour
Queue
95th /
Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
Queue
95th /
Max
(ft)
Lane
LOS
Delay
(sec)
Approach
LOS
(sec)
Overall
LOS
(sec)
2023
No-Build
Conditions
WBR -- 15 / 74 D1 271 D (27) 1
N/A
23 / 88 D1 341 D (34) 1
N/A NBT
NBR
--
75
0 / 5
0 / 11
--
--
--
-- -- 0 / 0
0 / 0
--
--
--
-- --
SBT -- 0 / 9 -- -- -- 0 / 9 -- -- --
2023
Build
Conditions
WBR -- 23 / 84 D1 291 D (29) 1
N/A
43 / 107 E1 411 E (41) 1
N/A NBT
NBR
--
75
0 / 0
0 / 0
--
--
--
--
--
--
0 / 11
0 / 0
--
--
--
-- --
SBT -- 0 / 0 -- -- -- 0 / 158 -- -- --
Improvements and/or revised lane configurations shown in BOLD.
*Due to limitations with HCM 6th TWSC reporting, a vehicle length of 25 feet was used to determine the 95th
percentile queue in feet.
1. Level of service for minor-street approach.
Capacity analysis of 2023 no-build and 2023 build traffic conditions indicates that the minor-
street approach is expected to operate at LOS D during the weekday AM and PM peak hours
with the exception of the weekday PM peak hour under 2023 build traffic conditions which
is expected to operate at LOS E. When comparing 2023 no-build traffic conditions to 2023
build traffic conditions, the minor-street is expected to degrade by one level from LOS D to
LOS E; however, these levels-of-service are not common for stop-controlled minor-street
approaches with heavy mainline traffic volumes. It is expected that the signalized intersection
of US 17 and Mendenhall Drive / Marsh Oaks Drive will meter traffic traveling northbound
on US 17 and provide sufficient gaps to service the minor-street traffic at this intersection.
Based on the queueing analysis results, no significant queueing problems are expected at this
intersection as queues are expected to increase by at most 19 feet (approximately 1 vehicle)
between 2023 no-build and 2023 build traffic conditions.
Marsh Oaks Development | 34
8. CONCLUSIONS
This Traffic Impact Analysis was conducted to determine the potential traffic impacts of the
proposed Marsh Oaks development, to be located along US 17 (Market Street) and Marsh
Oaks Drive in New Hanover County, North Carolina. The proposed development is expected
to be a commercial development and be built-out in 2023. Site access is proposed via one (1)
full movement driveway along Marsh Oaks Drive as well as one (1) right-in/right-out (RIRO)
driveway on US 17 (Market Street). The full movement driveway on Marsh Oaks Drive is
proposed to be aligned with the Amberleigh Shores Driveway. It should be noted that these
driveway connections are expected to be constructed by the Primrose School of Mayfaire
development.
The study analyzes traffic conditions during the weekday AM and PM peak hours for the
following scenarios:
• 2022 Existing Traffic Conditions
• 2023 No-Build Traffic Conditions
• 2023 Build Traffic Conditions
Trip Generation
It is estimated that the proposed development will generate approximately 83 primary trips
(54 entering and 29 exiting) during the weekday AM peak hour and 95 primary trips (41
entering and 54 exiting) during the weekday PM peak hour.
Adjustments to Analysis Guidelines
Capacity analysis at all study intersections was completed according to NCDOT Congestion
Management Guidelines. Refer to section 6.1 of this report for a detailed description of any
adjustments to these guidelines made throughout the analysis.
Intersection Capacity Analysis Summary
All the study area intersections (including the proposed site driveways) are expected to
operate at acceptable levels-of-service under existing and future year conditions with the
exception of those identified in Section 7 of this report.
Marsh Oaks Development | 35
9. RECOMMENDATIONS
Based on the findings of this study, specific geometric improvements have been identified
and are recommended to accommodate future traffic conditions. See a more detailed
description of the recommended improvements below. Refer to Figure 13 for an illustration
of the recommended lane configuration for the proposed development.
Improvements by Others
US 17 (Market Street) and Mendenhall Drive / Marsh Oaks Drive
• Extension of the southbound left turn lane on US 17 to 400 feet of storage with an
appropriate deceleration and taper length.
US 17 (Market Street) and Primrose Site Access 1
• Provide a northbound right turn lane with 75 feet of storage and appropriate
deceleration and taper.
• Construct the site access as right in/right out only, with one ingress lane and one
egress lane.
• Provide stop control for the westbound approach and 100 feet of internal protected
stem.
Marsh Oaks Drive and Primrose Site Access 2
• Construct the site access with one ingress and one egress lane.
• Provide stop control for the southbound approach and 100 feet of internal protected
stem.
Improvements by Developer
Due to committed improvements by other developments and low impacts to the study
intersections, no additional improvements are recommended by the developer.
Marsh Oaks
Wilmington, NC
Scale: Not to Scale
Signalized Intersection
Unsignalized Intersection
LEGEND
Existing Lane
X'Storage (In Feet)
Improvement by Others
Figure 14
Recommended Lane
Configurations
Right-in/right-out Intersection
36
N
Mendenhall
Drive
17
Marsh Oaks
Drive
17
Hays
Lane
Commercial
Driveway
Am
b
e
r
l
e
i
g
h
S
h
o
r
e
s
Dr
i
v
e
w
a
y
Pr
i
m
r
o
s
e
Si
t
e
D
r
i
v
e
2
Primrose
Site Drive 1 SITE
40
0
'
20
0
'
150'
150'
75'
175'300'300'40
0
'
40
0
'
15
0
'
67
5
'
87
5
'
75
'