HomeMy WebLinkAbout20120285_Appendix C_Supporting Traffic Info for Chapt 2_20101222
APPENDIX C APPENDICES
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
APPENDIX C
SUPPORTING INFORMATION FOR CHAPTER 2 -
ALTERNATIVES CONSIDERED
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-1
APPENDIX C – SUPPORTING TRAFFIC INFORMATION
FOR CHAPTER 2 – ALTERNATIVES
CONSIDERED
Contents
C.1 TRAFFIC OPERATIONS ON EXISTING ROADS
C.1.1 BACKGROUND AND ANALYSIS METHODOLOGY
C.1.2 REGIONAL STATISTICS FROM THE 2030 TRAVEL DEMAND MODEL
C.1.3 TRAFFIC VOLUMES AND LEVELS OF SERVICE ON AREA ROADWAYS
C.1.3.1 I-85
C.1.3.2 US 29-74
C.1.3.3 US 321
C.1.3.4 I-485
C.2 MOBILITY AND CONNECTIVITY MEASURES
C.1.1 MOBILITY AND CONNECTIVITY WITHIN GASTON COUNTY
C.1.2 MOBILITY AND CONNECTIVITY BETWEEN GASTON COUNTY AND MECKLENBURG COUNTY
C.1 TRAFFIC OPERATIONS ON EXISTING ROADS
C.1.1 BACKGROUND AND ANALYSIS METHODOLOGY
Travel Demand Modeling. The 2030 Metrolina travel demand model used for the project
traffic forecasts covers a thirteen-county region (including Gaston County and Mecklenburg
County) within a single model. The 2030 Metrolina travel demand model also uses population
and land use forecasts that extend out to 2030. The April 13, 2006, version of the 2030 Metrolina
travel demand model was used because this was the version current at the time the updated
forecasting activities began. The Metrolina travel demand model is updated on a continual
basis.
Using the 2030 Metrolina travel demand model, the following scenarios were modeled to
estimate their effects on 2030 traffic operations region-wide and along existing major roadways:
the No-Build Alternative, an Improve Existing Roadways Alternative Scenarios 4+/4a, and New
Location Alternative Non-Toll and Toll Scenarios (using representative DSA 64). The forecasts
are documented in the Gaston East-West Connector Traffic Forecasts for Toll Alternatives
(Martin/Alexiou/Bryson, August 2008), incorporated by reference.
The modeled Improve Existing Roadways Alternative Scenario 4+/4a included widening I-85 to
eight lanes where it is currently six lanes (west of Exit 26) and to ten lanes where it is currently
eight lanes (east of Exit 26, where the demand is highest). These improvements are a mix of the
improvements proposed under the two individual Scenarios (4+ and 4a). Scenario 4+ includes
widening I-85 to eight lanes west of Exit 26. Scenario 4a included widening I-85 to eight lanes
west of Exit 19 and to ten lanes east of Exit 19. Improvements to US 29-74 are the same under
both scenarios. The 2025 forecasted daily traffic volumes for the two scenarios were almost the
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-2
same, and 2025 regional statistics were similar, so it was expected that the 2030 forecasts would
be similar between the two scenarios. Therefore, the Alternative Scenario 4+/4a combination of
improvements modeled in the 2030 Metrolina travel demand model provided a representative
forecast that could be used for either individual scenario. For simplicity, it is labeled as
“Scenario 4” in this Draft EIS.
Improve Existing Roadways Alternative Scenario 8 was not modeled because it was not
necessary, as this alternative was eliminated due to its impacts to the human and natural
environments. Section 2.2.6.4 includes more discussion on why these scenarios were
eliminated.
Of the three representative DSAs used to create forecasts for the New Location Alternative
(Non-Toll and Toll Scenarios), DSA 64 was used to evaluate effects region-wide and on existing I-
85, I-485, US 29-74, and US 321 for comparison to the No-Build Alternative and Improve
Existing Roadways Alternative Scenarios 4. Based on year 2025 travel-demand modeling efforts
for the DSAs as non-toll facilities, the DSAs were relatively close in projections, with DSA 64
appearing to divert the least traffic from I-85 and US 29-74. Using this alternative as a
representative alternative provides an estimate of the lower range of the project’s ability to
reduce traffic volumes on the area’s major roadways as either a toll facility or a non-toll facility.
Other DSAs were estimated to be as or more effective at diverting traffic.
Level of Service Analysis Methodology. Traffic operations analysis was conducted to
calculate levels of service for major roadways surrounding the proposed project (I-85, I-485,
US 321, and US 29-74) under various build and no-build scenarios. This analysis is documented
in the Traffic Operations Technical Memorandum for I-85, I-485, US 29-74, and US 321 Under
Various Scenarios (PBS&J, July 2008), incorporated by reference.
Level of service (LOS) is a “qualitative measure describing operational conditions within a traffic
stream” (Transportation Research Board 2000: 2-2). The LOS is defined with letter designations
ranging from A to F that can be applied to both roadway segments and intersections. LOS A
represents the best operating condition and LOS F the worst.
All analysis was performed in accordance with the NCDOT Congestion Management Capacity
Analysis Guidelines (February 15, 2006), as applicable. A freeway capacity analysis was
performed for the I-85 and I-485 mainlines using the North Carolina Level of Service (NC LOS)
software, Version 1.3. In addition, an arterial capacity analysis was performed for US 29-74 and
US 321 using the same software.
A detailed analysis for merging/diverging/weaving was not conducted for every scenario because
of the level of detail necessary to evaluate concepts and trends at this stage of alternatives
development. Only basic segments between interchanges and intersections were modeled.
However, the merging/diverging/weaving traffic could influence the LOS along the freeway. The
effect could be to degrade LOS, with the possible result being the need for collector-distributor
roads or auxiliary lanes. This type of effect would occur under any of the Improve Existing
Alternative and New Location Alternative scenarios.
C.1.2 REGIONAL STATISTICS FROM THE 2030 TRAVEL DEMAND MODEL
Table C-1 lists the regional statistics for the year 2030 for the No-Build Alternative, Improve
Existing Roadways Alternative Scenario 4, and the New Location Alternative Non-Toll and Toll
Scenarios. The statistics are for the portion of the network in Gaston County and include: total
and congested vehicle miles traveled (VMT), total and congested vehicle hours traveled (VHT),
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-3
and congested VMT and congested VHT as percentages of total VMT and VHT.
Comparison of VMT and VHT. The values in Table C-1 indicate that either widening I-85
(Improve Existing Roadways Alternative Scenario 4) or constructing a New Location Alternative
as either a toll or non-toll facility would result in higher total VMT and VHT compared to the No-
Build Alternative, with the New Location Alternative Toll Scenario having the smallest increase
over the No-Build Alternative.
The 2030 VMT would be about the same for the New Location Alternative Scenarios and the
Improve Existing Roadways Alternative Scenario 4, but the VHT would be less with a new
location facility. This data indicates that the new location facility would provide a quicker trip
for many drivers in Gaston County in 2030.
Under Improve Existing Roadways Alternative Scenario 8, the VMT and VHT would likely be
higher than under Scenario 4 because more capacity is added to the network, enabling travelers
to make longer trips.
TABLE C-1: 2030 Regional Travel Demand Model Statistics for Gaston County For
Various Scenarios
2030 Vehicle Miles
Traveled (VMT)
in 1000’s
2030 Vehicle Hours
Traveled (VHT)
in 1000’s Scenario Description
Daily AM Peak PM Peak Daily AM
Peak
PM
Peak
1 No‐Build Alternative 8,512 2,058 2,308 234.9 70.3 78.6
4 Improve Existing Roadways
Alternatives 9,559 2,431 2,580 267.0 84.5 89.1
Non‐Toll New Location Alternative 9,646 2,316 2,589 255.6 74.0 85.3
Toll New Location Alternative 9,473 2,294 2,569 255.8 75.2 84.5
2030 Congested VMT
in 1000’s
2030 Congested VHT
in 1000’s
Daily AM Peak PM Peak Daily AM
Peak
PM
Peak
1 No‐Build Alternative 1,536 691 783 129.2 66.6 58.5
4 Improve Existing Roadways
Alternatives 1,884 875 911 168.4 82.3 79.0
Non‐Toll New Location Alternative 1,648 689 875 144.1 62.4 75.6
Toll New Location Alternative 1,528 698 758 124.0 59.0 59.7
2030 Congested VMT
as a Percent of Total VMT
2030 Congested VHT
as a Percent of Total VHT
Daily AM Peak PM Peak Daily AM
Peak
PM
Peak
1 No‐Build Alternative 18.0% 33.6% 33.9% 55.0% 94.7% 74.4%
4 Improve Existing Roadways
Alternatives 19.7% 36.0% 35.3% 63.1% 97.4% 88.7%
Non‐Toll New Location Alternative 17.1% 29.7% 33.8% 56.4% 84.3% 88.6%
Toll New Location Alternative 16.1% 30.4% 29.5% 48.5% 78.5% 70.7%
Source: Gaston East‐West Connector Traffic Forecasts for Toll Alternatives, Martin/Alexiou/Bryson, August 2008.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-4
The main variable in the Metrolina travel demand model affecting trips in the project area is
travel time. In general, the total number of trips changes very little between the alternatives
modeled using the 2030 Metrolina model; however, their destinations are different. For example,
a large concentration of residential development is projected in Gaston County not far west of the
Catawba River (and in the vicinity of the proposed river crossing), and a large employment
concentration is projected to the east of the river (within the Dixie-Berryhill area). In the No-
Build scenario, a trip from one of these Gaston County residences to one of these Mecklenburg
County employers (for work, shopping, or other purposes) that might be approximately 2 or 3
miles away requires a longer drive either to I-85 and back down, or traveling down to NC 49 and
then back north. Most of these trip purposes can be satisfied more efficiently by remaining on
the same side of the river, even though the trip attractor on the other side may be more
desirable. Because of the travel costs involved, the less desirable destination may be selected.
Once a new river crossing is introduced (Toll or Non-Toll Scenario), a desirable destination that
may have required a 20-mile, 35-minute trip might now be no more than a 3-mile drive requiring
less than 10 minutes. The model shows a shift in the distribution of trips to new destinations, in
addition to changes in the routes selected by some trips that are crossing the river to the same
destination. Furthermore, there is a “domino effect” in the travel demand model: the re-
distribution and re-assignment of traffic reduces congestion on some secondary routes (and
increases it on others), resulting in another round of re-distribution and re-assignment. This
cycle is repeated for several iterations of the travel demand model, until a stable equilibrium is
achieved, in which no one can significantly reduce their travel costs by switching routes or
destinations.
The widening of I-85 (Improve Existing Roadways Alternative Scenario 4) has a similar, though
less pronounced, effect. Additional lanes provide more capacity, reducing both congestion and
travel times, so some cross-river destinations become close enough (in terms of travel times) to
cause a shift, and total crossing traffic volumes increase. The re-routing effect is less pronounced
under this scenario, as is the domino (or ripple) effect described above.
Comparison of Congested VMT and VHT. The values in Table C-1 indicate that Improve
Existing Roadways Alternative Scenario 4 and the New Location Alternative Non-Toll Scenario
would result in the most congested VHT and VMT. The New Location Alternative Toll Scenario
and the No-Build Alternative result in about the same congested VMT and VHT, with the New
Location Alternative Toll Scenario performing slightly better. Again, these results from the
regional travel demand model are likely the result of high latent demand for additional capacity
over the Catawba River between Gaston County and Mecklenburg County.
As a percent of total VMT and total VHT, the congested VMT and congested VHT are highest for
the Improve Existing Roadways Alternative Scenario 4 compared to the No-Build Alternative
and the New Location Alternatives (Toll and Non-Toll Scenarios). This may be due to higher
congestion on roadways leading to the improved I-85, and the congestion projected to still occur
on the improved I-85. The New Location Alternatives have the lowest percentages, with the Toll
Scenario demonstrating the best performance.
As individual scenarios, Scenario 4+ likely would have slightly higher congested VMT and VHT
values than what is shown in Table C-1 for the combined Scenario 4, and Scenario 4a may have
slightly lower congested VMT and VHT. This is because Scenario 4a does provide some
additional capacity on I-85 (an additional lane in each direction between Exit 19 and Exit 26)
compared to the combined Scenario 4. However, the lower values for congested VMT and VHT
that may occur under Scenario 4a may be offset by slightly higher projected traffic volumes, and
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-5
would still be substantially higher than the values for the No-Build Alternative and the New
Location Alternative (Toll and Non-Toll Scenarios).
It is notable that the 2030 Metrolina travel demand model indicates that adding capacity on I-85
under the Improve Existing Roadways Alternative Scenario 4 is projected to increase congestion
throughout the network. This projected outcome is somewhat counter-intuitive. Adding lanes to
I-85 increases capacity, which increases travel speeds, so travelers continue to shift to use I-85.
Potential demand exceeds the additional capacity, and traffic keeps shifting to I-85 until
congestion builds to the point at which a new equilibrium point is reached in the model. So,
although I-85 has been widened, much of it remains congested, but with much higher volumes of
traffic. However, the widened I-85 is not as severely congested as under the No-Build
Alternative.
The other factor affecting the Improve Existing Roadways Alternative Scenario 4 results is that
most of the trips diverted to the improved I-85 do not produce significant congestion benefits on
other facilities. The New Location Alternative (Toll or Non-Toll Scenarios) has an added benefit
of diverting traffic from congested facilities onto roads with reserve capacity (in general). When
I-85 is widened under the Improve Existing Roadways Alternative Scenario 4, motorists diverted
onto I-85 tend to come from highly-congested routes that get more congested carrying vehicles to
I-85, so there is an increase in congested VMT. Because there are so few options for crossing the
Catawba River, individual drivers can still benefit from taking a congested route, even while
system-wide performance suffers. Braess’s Paradox is the term for this phenomenon, recognized
in complex networks (including telephone and Internet service) where increasing capacity on
specific links can, in certain instances, increase congestion overall.
If Improve Existing Roadways Alternative Scenario 8 were modeled, the congested VMT totals
would be expected to improve over Scenario 4, but likely not enough to show the same
improvements in congested VMT achieved by the New Location Alternatives (Non-Toll or Toll
Scenarios). Widening north-south feeder roads under Scenario 8 would allow more traffic to be
delivered to the same bottlenecks faster. Travelers would have wider crossroads/feeder roads to
idle on while waiting to reach I-85. The effects would be to have shorter queues and higher
levels of services for other trips on the crossroads/feeder roads, but this would not produce
enough improvements to congestion to compete with any of the New Location Alternatives.
C.1.3 TRAFFIC VOLUMES AND LEVELS OF SERVICE ON AREA ROADWAYS
C.1.3.1 I-85
Table C-2 shows the 2030 Annual Average Daily Traffic (AADT) and levels of service projected
for I-85 from Exit 10 (US 29-74) to Exit 30 (I-485) within the project study area under various
scenarios. The projected AADT under each scenario are graphically compared in Exhibit 2-1.
Improvements to I-85 under the Improve Existing Roadways Alternative Scenario 4 result in
additional traffic volumes being attracted to I-85. Under the New Location Alternatives (Toll
and Non-Toll Scenarios), traffic volumes increase slightly on I-85 west of US 321 and decrease
east of US 321 compared to the No-Build Alternative, as travelers divert to the new highway.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-6
TABLE C-2: Year 2030 Traffic Volumes and Levels of Service on I-85 For Various Scenarios
No‐Build
Alternative
Improve Existing
Roadways Alternative
Scenario 4
New Location
Alternative
Non‐Toll Scenario
New Location
Alternative
Toll Scenario
Between I‐85 Exits
(West to East)
AADT1 LOS2 AADT1 LOS2 AADT1 LOS2 AADT1 LOS2
Exit 10B (US 29‐74) to
Gaston East‐West Connector 105,000 E 115,200 D 111,200 E 111,800 E
Gaston E‐W Connector to
Exit 13 (SR 1307 – Edgewood Rd) 105,000 F 115,200 E 102,100 E 106,000 E
13 to 14 (NC 274 – Bessemer
City Rd) 115,400 F 131,000 E 116,200 F 120,400 F
14 to 17 (US 321) 119,200 F 139,600 E 121,200 F 125,200 F
17 to 19 (Ozark Ave) 134,600 F 157,200 F 132,800 F 138,400 F
19 to 20 (NC 279) 147,200 F 174,600 F (E)3 142,200 F 148,200 F
20 to 21 (Cox Rd) 151,000 F 180,000 F (E) 3 145,400 F 151,400 F
21 to 22 (Redbud Dr) 153,000 F 185,400 F (E) 3 144,600 F 149,600 F
22 to 23 (NC 7 – McAdenville Rd) 161,600 F 195,200 F 149,800 F 157,400 F
23 to 26 (Abbey College) 169,200 F 202,200 F 155,000 F 162,800 F
26 to 27 (NC 273‐Park St) 178,600 F 212,400 F 163,000 F 171,000 F
27 to 29 (Sam Wilson Rd) 193,600 F 228,200 F 175,800 F 185,200 F
29 to 30 (I‐485) 198,400 F 234,600 F 181,200 F 190,800 F
1. AADT = Annual Average Daily Traffic volumes
2. LOS = Level of Service
3. LOS F for Scenario 4+ and LOS E for Scenario 4a
Source: Traffic Operations Technical Memorandum for I‐85, I‐485, US 29‐74, and US 321 Under Various Scenarios, PB&J, July 2008
The graph in Exhibit C-1 shows the traffic volume information from Table C-2. As the exhibit
indicates, there is so much latent demand in the study area for highway travel that adding one
to two lanes in each direction on I-85 under Scenario 4 attracted an average of 17 percent more
vehicles per hour compared to the No-Build Alternative. Widening the north/south feeder roads
to the Interstate (as suggested under Scenario 8) would be expected to attract even more vehicles
to I-85.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-7
Exhibit 2-1: 2030 Traffic Volumes on I-85 for Various Scenarios
50,000
75,000
100,000
125,000
150,000
175,000
200,000
225,000
250,000
I‐85 from West to East ‐ Exit 10B to Exit 30
20
3
0
Av
e
r
a
g
e
Da
i
l
y
Tr
a
f
f
i
c
Vo
l
u
m
e
No‐Build Alternative
Improve Existing Roadways
Scenarios 4+/4a
New Location Non‐Toll
Scenario
New Location Toll Scenario
I-85 is projected to operate primarily at LOS E or F, regardless of the alternative. Under the
Improve Existing Roadways Alternative Scenario 4, most improvements in traffic flow achieved
by adding additional lanes would be offset by the increase in traffic volumes attracted to the
facility.
Under the New Location Alternative (either the Toll or Non-Toll Scenario), traffic flow would
improve somewhat due to decreases in traffic volumes compared to the No-Build Alternative,
even though the LOS remains LOS F.
C.1.3.2 US 29-74
Table C-3 shows the AADT volumes and levels of service projected for US 29-74 in the project
study area under various scenarios.
TABLE C-3: Year 2030 Traffic Volumes and Levels of Service on US 29-74 For Various
Scenarios
No‐Build
Alternative
Improve Existing
Roadways
Alternative
Scenario 4
New Location
Alternative
Non‐Toll Scenario
New Location
Alternative
Toll Scenario US 29‐74 Segment
(West to East)
AADT1 LOS2 AADT1 LOS2 AADT1 LOS2 AADT1 LOS2
Sparrow Springs Rd to Gaston
East‐West Connector
37,200 D 41,900 B 48,400 F 43,600 F
Gaston East‐West Connector
to Edgewood Rd 37,200 D 41,900 B 33,600 E 35,500 E
Edgewood Rd to Shannon
Bradley Rd 35,600 C 37,300 B 32,200 C 36,400 C
Shannon Bradley Rd to
Myrtle School Rd 35,400 E 37,200 C 32,100 D 36,300 F
Myrtle School Rd to
Bessemer City Rd 32,200 F 34,300 F 29,700 F 34,600 F
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-8
TABLE C-3: Year 2030 Traffic Volumes and Levels of Service on US 29-74 For Various
Scenarios
No‐Build
Alternative
Improve Existing
Roadways
Alternative
Scenario 4
New Location
Alternative
Non‐Toll Scenario
New Location
Alternative
Toll Scenario US 29‐74 Segment
(West to East)
AADT1 LOS2 AADT1 LOS2 AADT1 LOS2 AADT1 LOS2
Bessemer City Rd to
Linwood Rd 21,500 D 21,300 D 20,000 D 23,100 D
Linwood Rd to
US 321 (Chester Rd) 16,400 D 18,600 D 17,100 D 19,700 D
US 321 (Chester Rd) to Avon
St 21,800 D 23,800 E 21,100 D 23,000 D
Avon St to
Thomas St/Belvedere Ave 22,700 D 23,800 D 22,400 D 24,700 D
Thomas St/Belvedere Ave to
NC 279 (New Hope Rd) 27,100 C 28,400 C 26,300 C 32,100 D
NC 279 (New Hope Rd) to
Cox Rd/Armstrong Park Rd 24,700 C 23,000 C 22,300 C 26,000 C
Cox Rd/Armstrong Park Rd to
Franklin Square 39,200 D 35,000 D 36,700 D 39,900 D
Franklin Square to
Lineberger Rd 39,200 F 35,400 E 40,300 F 43,500 F
Lineberger Rd to
S Main St/Redbud Dr 39,500 D 35,400 D 38,300 D 40,700 D
S Main St/Redbud Dr to
Wesleyan Dr/Market St 42,300 D 39,300 D 38,700 D 40,400 D
Wesleyan Dr/Market St to
Lakewood Rd 59,700 F 56,800 F 53,000 F 56,100 F
Lakewood Rd to
NC 273 (Park St) 60,100 F 58,100 F 47,500 D 51,800 F
NC 273 (Park St) to
NC 7 (Catawba St) 72,700 F 71,200 F 56,100 F 61,500 F
NC 7 (Catawba St) to
Old Dowd Rd 70,500 F 69,900 F 58,600 F 63,900 F
Old Dowd Rd to
Sam Wilson Rd 52,600 F 52,100 E 39,600 F 45,400 F
Sam Wilson Rd to
I‐485 SB Ramps 58,400 F 59,000 F 48,400 F 51,000 F
I‐485 SB Ramps to
I‐485 NB Ramps 55,100 F 57,300 F 47,000 F 49,300 F
East of I‐485 NB Ramps 45,000 F 48,400 E 38,800 F 40,800 F
1. AADT = Annual Average Daily Traffic volumes
2. LOS = Level of Service
Source: Traffic Operations Technical Memorandum for I‐85, I‐485, US 29‐74, and US 321 Under Various Scenarios, PB&J, July 2008
As shown in Table 2-5, compared to the No-Build Alternative, the New Location Alternative
Non-Toll Scenario is the most effective at reducing traffic volumes on US 29-74, with the most
reduction on the eastern end of the project area. The Improve Existing Roadways Alternative
Scenario 4 are the least effective, resulting in slightly higher traffic volumes on US 29-74 west of
NC 279 (New Hope Road) compared to the No-Build Alternative. This is likely due to the fact
that travelers wanting to use the widened I-85 under Improve Existing Roadways Alternative
Scenario 4 would use portions of improved US 29-74 to get there. The New Location Alternative
Toll Scenario would have similar traffic volumes on US 29-74 as the Improve Existing Roadways
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-9
Alternative Scenario 4, except east of South Main Street/Redbud Drive, where traffic volumes
would be less compared to the No-Build Alternative.
The higher volumes on the segment from Edgewood Road to Shannon Bradley Road that would
occur under the New Location Alternatives (compared to the No-Build Alternative) are due to the
new interchange providing access to the Gaston East-West Connector. This also results in lower
volumes between Shannon Bradley Road and Myrtle School Road for the New Location
Alternatives compared to the Improve Existing Roadways Alternative Scenario 4.
Under the No-Build Alternative, US 29-74 is projected to operate primarily at LOS D or better
west of McAdenville and LOS F east of McAdenville. Under the Improve Existing Roadways
Alternative Scenario 4, LOS would improve compared to the No-Build Alternative west of Myrtle
School Road, where US 29-74 would be widened to six lanes. Under the New Location
Alternative (Non-Toll and Toll Scenarios), the LOS would be similar to the No-Build Alternative,
even though traffic volumes would be less.
C.1.3.3 US 321
Improve Existing Roadway Alternatives Scenario 4 would result in an increase in traffic volumes
along US 321 in the study area by an average of approximately 15 percent, as more people use
US 321 to travel to a widened I-85. Compared to the Improve Existing Roadways Alternatives,
the New Location Alternatives would increase traffic volumes more on US 321 south of the
Gaston East-West Connector, but decrease the volumes from the Gaston East-West Connector
north to downtown Gastonia. North of downtown, the volume increases would be about the same
between the New Location Alternatives and the Improve Existing Roadways Alternatives.
Levels of service along US 321 are similar for all evaluated alternatives. Levels of service are
LOS D or better through the project area, except near the I-85 ramps, where LOS would be
LOS F.
C.1.3.4 I-485
Improve Existing Roadways Alternative Scenario 4 would result in higher traffic volumes on
I-485 compared to the No-Build Alternative. The New Location Alternatives (Toll and Non-Toll)
would result in higher traffic volumes south of the new Gaston East-West Connector interchange
at I-485, and slightly less traffic volumes north of the new interchange.
I-485 within the study area is projected to operate primarily at LOS E under the No-Build
Alternative. Under the Improve Existing Roadways Alternative Scenario 4, LOS would degrade
to LOS F. Under the New Location Alternatives (Toll and Non-Toll Scenarios), the LOS would
be LOS F on I-485 south of the Gaston East-West Connector and LOS E north of the Gaston
East-West Connector.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-10
C.2 MOBILITY AND CONNECTIVITY MEASURES
C.2.1 MOBILITY AND CONNECTIVITY WITHIN SOUTHERN GASTON COUNTY
South of I-85 in southern Gaston County, a lack of connecting east-west roadways makes travel
circuitous and limits mobility. Currently, there are no continuous east-west routes in southern
Gaston County. The roads in southern Gaston County generally run in a north-south direction.
As can be seen in Figure 1-3, a person wishing to travel from the residential subdivisions on the
Belmont peninsula (the land between the South Fork Catawba River and Catawba River) to
businesses and industries along US 321 in southern Gaston County cannot do so directly. They
must first travel north on NC 273 (Southpoint Road) to use westbound I-85 or US 29-74 to
US 321, then south on US 321 or travel a circuitous route that might include NC 273 (Armstrong
Road), NC 279 (South New Hope Road), SR 2435 (Union New Hope Road), NC 274 (Union Road),
SR 2416 (Robinson Road), SR 2412 (Little Mountain Road), SR 2420 (Forbes Road) to US 321.
NC 273, NC 279, SR 2435, NC 274, SR 2416, and SR 2420 are all two-lane roadways with no
access control.
Using the existing routes in southern Gaston County described above, a person would travel
approximately 17 miles across southern Gaston County. A person using Southpoint Road to I-85
to US 321 would travel approximately 22 miles. A person using the Gaston East-West Connector
would have approximately an 11-mile trip.
The approximate travel times for a person traveling within southern Gaston County were
estimated using the travel time contour feature of the 2030 Metrolina travel demand model. The
model generates contour lines showing various travel time increments (in this case, 10-minute
increments) from an input starting point (origin), and can also give approximate travel times to
specified destinations. The travel time contours were run for the morning peak hour for the
No-Build Alternative, Improve Existing Roadways Alternative Scenario 4, and the New Location
Alternative Toll Scenario. As representative trips for the study area, selected origins included
the Belmont peninsula near the intersection of Southpoint Road and Armstrong Road, and
southwest Gaston County near the intersection of Lewis Road and Chapel Grove Road. Selected
destinations were US 321 at Robinson Road, downtown Gastonia, downtown Bessemer City, and
Daniel Stowe Botanical Garden.
Table C-4 shows the results for the modeled origins and destinations within Gaston County.
Travel times for travel within southern Gaston County would lengthen somewhat under the
Improve Existing Roadway Alternative Scenario 4. Under these scenarios, more vehicles are
using the network roads to reach I-85 and US 29-74, which reduces speeds on roadways
throughout the network. Travel times under Scenario 8 may be slightly less, as more capacity is
provided on north-south feeder roads, but these roads are used only for short distances in east-
west cross-county travel. Also, if the new capacity on I-85 were tolled, this would not have an
effect on travel within southern Gaston County.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-11
TABLE C-4: Estimated Travel Times for Trips within Gaston County for Various Scenarios
Approximate Travel Time in 2030 (minutes)
No‐Build
Alternative
Improve Existing
Roadways
Alternative
Scenario 4
New Location
Alternative ‐ Toll
Scenario Origin Destination Peak
Period
Travel Time Travel
Time
Time
Change1
Travel
Time
Time
Change1
US 321 at Robinson Rd AM 22 25 ↑ 3 13 ↓ 9
Downtown Gastonia AM 20 22 ↑ 2 18 ↓ 2
Belmont Peninsula –
Southpoint Rd/
Armstrong Rd
Intersection Downtown Bessemer City AM 27 32 ↑ 5 25 ↓ 2
Daniel Stowe Botanical
Garden AM 30 31 ↑ 1 22 ↓ 8
Downtown Gastonia AM 13 13 0 10 ↓ 3
Southwest Gaston
County – Lewis Rd/
Chapel Grove Rd
Intersection Downtown Bessemer City AM 15 14 ↓ 1 12 ↓ 3
1. Time change is the difference compared to the No‐Build Alternative.
Source: Travel Time Contour Maps produced by M/A/B using the 2030 Metrolina travel demand model, July 2008. Included as
Appendix C in the Addendum to the Final Alternatives Development and Evaluation Report, PBS&J, October 2008.
Under the New Location Alternative (Toll Scenario), travel times would noticeably improve for
cross-county travel in southern Gaston County. For example, travel from the Belmont Peninsula
westward to US 321 would be reduced by about 9 minutes (about 40 percent) compared to the
No-Build Alternative. Likewise, travel times from southwest Gaston County eastward to the
Daniel Stowe Botanical Garden area would be reduced about 8 minutes (about 27 percent)
compared to the No-Build Alternative. Travel times under the New Location Alternative (Non-
Toll Scenario) are expected to be approximately the same as under the Toll Scenario.
The need for improved connectivity and east-west mobility within southern Gaston County will
continue to grow as the population in this area increases. Between 1990 and 2000, southeastern
Gaston County had the largest population increase in the county. According to the Gaston
County Comprehensive Plan, the southeastern part of the county is expected to continue
experiencing high residential growth through 2020.
C.2.2 MOBILITY AND CONNECTIVITY BETWEEN GASTON COUNTY AND
MECKLENBURG COUNTY
As was estimated for travel within southern Gaston County, the travel time contour feature of
the 2030 Metrolina travel demand model also was used to estimate travel times for various
origins and destinations between Gaston County and Mecklenburg County. The selected origins
included the Belmont peninsula near the intersection of Southpoint Road and Armstrong Road,
southwest Gaston County near the intersection of Lewis Road and Chapel Grove Road, south
Gastonia near the intersection of Hoffman Road and Robinwood Road (about halfway between
the New Location Alternative corridors and I-85), and Charlotte-Douglas International Airport.
Table C-5 shows the results for the modeled origins and selected destinations between the two
counties.
APPENDIX C
APRIL 2009 GASTON EAST-WEST CONNECTOR DEIS
C-12
TABLE C-5: Estimated Travel Times for Trips between Gaston and Mecklenburg Counties
for Various Scenarios
Approximate Travel Time in 2030 (minutes)
No‐Build
Alternative
Improve Existing
Roadways Alternative
Scenario 4
New Location
Alternative – Toll
Scenario
Origin Destination Peak
Period
Travel Time Travel
Time
Time
Change1
Travel
Time
Time
Change1
Belmont Peninsula –
Southpoint Rd/
Armstrong Rd
Intersection
Charlotte‐Douglas
International Airport AM 57 65 ↑ 8 34 ↓ 23
Southwest Gaston
County – Lewis Rd/
Chapel Grove Rd
Intersection
Charlotte‐Douglas
International Airport AM 83 87 ↑ 4 60 ↓ 23
Charlotte‐Douglas
International Airport AM 68 75 ↑ 7 50 ↓ 18 South Gastonia –
Hoffman Rd/
Robinwood Rd
Intersection
West of I‐485 near Steele
Creek Parkway AM 55 62 ↑ 7 45 ↓ 10
Southpoint Rd near
Southpoint High School PM 52 58 ↑ 6 29 ↓ 23
Daniel Stowe Botanical
Garden PM 62 69 ↑ 7 34 ↓ 28
US 321 at Robinson Rd PM 66 85 ↑ 19 45 ↓ 21
Downtown Gastonia PM 57 75 ↑ 18 46 ↓ 11
Charlotte‐Douglas
International Airport
Downtown Bessemer City PM 66 80 ↑ 14 57 ↓ 9
1. Time change is the difference compared to the No‐Build Alternative.
Source: Travel Time Contour Maps produced by M/A/B using the 2030 Metrolina travel demand model, July 2008. Included as
Appendix C in the Addendum to the Final Alternatives Development and Evaluation Report, PBS&J, October 2008.
Like travel within southern Gaston County, travel times for travel between Gaston and
Mecklenburg Counties would lengthen under the Improve Existing Roadway Alternative
Scenario 4 compared to the No-Build Alternative. If the new capacity on I-85 were tolled, travel
time savings may improve, but some of these savings would be offset because vehicles would still
need to drive on congested roadways to reach the Interstate. Also, for inter-county travel,
travelers must use I-85 or US 29-74 to cross over the river, and this routing constrains traffic
flow. Travel times under Scenario 8 likely would be better, as more capacity is provided on
north-south feeder roads, but travel time savings would not reach the levels achieved by the New
Location Alternative.
Under the New Location Alternative (Toll Scenario), travel times savings would be substantial
for most inter-county trips. For example, a trip to/from southern Gaston County (Belmont
Peninsula or southwest Gaston County) or south Gastonia from/to Charlotte-Douglas
International Airport would take about 20 minutes less (30–40 percent reduction). A trip from
Charlotte-Douglas International Airport to downtown Gastonia or downtown Belmont would be
reduced by approximately 10 minutes (about a 15 percent reduction). Travel times under the
New Location Alternative (Non-Toll Scenario) are expected to remain approximately the same as
under the Toll Scenario.