20100752_Reports_19991019

PURPOSE AND NEED REPOR
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for :yT 3
ADMINISTRATIVE ACTION
ENVIRONMENTAL DOCUMENT
Proposed US 321 Improvements at Blowing Rock
Town of Blowing Rock
Watauga and Caldwell Counties
TIP No, R-2237C
State Project Number 8.T731301
US DEPARTMENT OF TRANSPORTATION
FEDERAL HIGHWAY ADMINISTRATION
AND THE
NORTH CAROLINA DEPARTMENT OF TRANSPORTATION
Cooperating Agencies
US Army Corps of Engineers
November 4, 1999
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Table of Contents
1. PURPOSE OF AND NEED FOR ACTION 1-1
1.1 Introduction 1-1
1.2 Project Need 1-1
1.3 Project Purpose 1-2
1.4 Background Information 1-2
1.4.1 Setting and Land Use 1-2
1.4.2 Population Growth 1-2
1.4.3 Project History 1-4
1.5 Thoroughfare Planning 1-4
1.5.1 Overview of the Thoroughfare Planning Process 1-4
1.5.2 Caldwell and Watauga County Thoroughfare Planning 1-4
1.5.3 North Carolina Transportation Improvement Program 1-5
1.6 Transportation Network and Operating Characterisitics 1-5
1.6.1 Existing Road Network 1-5
1.6.2 Roadway Characteristics and Posted Speeds 1-6
1.6.3 Sidewalks and Pedestrian Movements 1-6
1.6.4 Intersections and Access Control 1-6
1.6.5 Traffic Volumes 1-6
1.6.6 Level of Service 1-8
1.6.7 Accidents/Safety 1-11
1.7 Modal Interrelationships 1-13
1.8 Summary 1-13
List of Tables
Table 1-1 Existing (1998) and Forecast Average Daily Traffic (ADT) and
Forecast Peak Hour Volume 1-8
Table 1-2 Level of Service Criteria 1-9
Table 1-3 Design Hour Roadway Level of Service 1-10
Table 1-4 Peak Hour Intersection Level of Service 1-11
Table 1-5 Accident Rates' 1-12
List of Figures
Figure 1-1 Project Area 1-3
Figure 1-2 Existing and Forecast Average Daily Traffic 1-7
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1. PURPOSE OF AND NEED FOR ACTION
1.1 INTRODUCTION
The North Carolina Department of Transportation's (NCDOT, 1999) 2000-2006 Transportation
Improvement Program (TIP) includes a highway improvement project in Caldwell and Watauga
counties at Blowing Rock from SR 1500 (Blackberry Road) north to US 221 in Blowing Rock.
Consequently, studies are underway in accordance with the requirements set forth in the
National Environmental Policy Act (NEPA) of 1969, as amended. This Purpose and Need
Statement is the first phase in the preparation of an environmental document. Concurrence Point
No. 1 of the NEPA/404 Merger Process, developing the purpose and need for the proposed
action, should justify why the improvement must be implemented, should be as comprehensive
as possible, and should be updated as appropriate throughout the development process of the
proposed action.
1.2 PROJECT NEED
The primary needs of the proposed action include:
Traffic capacity deficiencies exist along US 321 within the project area and will
continue to worsen.
US 321 currently operates at a peak hour level of service (LOS) F between Blackberry
Road and Green Hill Road (in Blowing Rock). Since LOS F reflects traffic volumes
greater than the capacity of the road, it indicates high delays and basically no passing
opportunities exist during peak periods. A primary reason for this condition is the
mountainous terrain, which results in slow truck speeds. Within the balance of the
project area in Blowing Rock, the level of service is an unacceptable (LOS D/E) at all
locations along US 321.
In 2025, the road south of Green Hill Road would continue to operate at LOS F in the
peak periods, although delays will increase substantially as traffic grows. Operations on
US 321 through Blowing Rock would operate at LOS E between Green Hill Road and US
321 Business. Between US 321 Business and US 221, US 321 would operate at LOS F.
Traffic under these conditions would be extremely congested during peak periods.
Refer to Table 1-3 and Table 1-4 in section 1.6.6, "Level of Service," for the exact
locations expected to operate at undesirable levels of service and Table 1-2 for level of
service definitions.
Accident rates on existing US 321 within the Town of Blowing Rock are far higher
than statewide averages for similar roads.
The total accident rate for existing US 321 within Blowing Rock is 28 percent higher than
similar urban US routes in North Carolina. The non-fatal injury accident rate is 23 percent
higher, and the property damage accident rate is 30 percent higher than the state
comparative rate. One fatality occurred within the last three years. Narrow lanes and
poor sight distances, combined with turning vehicles at intersections and driveways
appear to explain the high levels of accidents on US 321 in Blowing Rock.
R-2237 NEPA/404 Merger Meeting 1-1 November 4, 1999
I
Refer to Table 1-5 in section 1.6.7, "Accidents/Safety," for more specifics on the types
and locations of accidents.
1.3 PROJECT PURPOSE
The primary purpose of the proposed action includes the following:
• Improve traffic flow and level of service on US 321 from Blackberry Road to US 221.
Without road improvements, the forecast traffic along this section of US 321 will exceed
the road's capacity, creating undesirable levels of service. The proposed improvement
will provide congestion relief.
Reduce accidents on US 321 within Blowing Rock.
Without road improvements, high accident rates are expected to continue. The numbers
of accidents will likely rise as traffic volumes continue to rise. Improvements could
increase sight distances by straightening curves and could provide separate lanes for
drivers turning left or an additional through lane.
1.4 BACKGROUND INFORMATION
1.4.1 Setting and Land Use
The project area is in western North Carolina and encompasses the northern part of Caldwell
County and the southern part of Watauga County, including the resort community of Blowing
Rock. (See Figure 1-1.) The project area extends well east of US 321 to encompass the
locations of potential bypass alternatives: Land use in the project area includes scattered rural
residential development in Caldwell County and eastern Blowing Rock, as well as concentrated
low-density residential, commercial, and recreational development in Blowing Rock both east
and west of US 321. Within Blowing Rock, US 321 passes through a district that is listed on the
National Register of Historic Places. US 321 passes adjacent to the Green Park Inn and the
Blowing Rock Country Club, which are included in the historic district. It also passes adjacent to
a residential structure individually listed on the National Register. Development along US 321 in
the southern portion of Blowing Rock is primarily low-density residential, while the primary
development along US 321 in the northern portion of Blowing Rock is highway commercial.
Development in Blowing Rock off of US 321 is primarily single-family residential with very few
commercial structures. The Blue Ridge Parkway is not crossed by the existing road but a
potential bypass alternative would pass under the Parkway in a tunnel.
1.4.2 Population Growth
Caldwell County's population grew 4.4 percent (67,746 to 70,709) from 1980 to 1990; between
1990 and 2000, the County is expecting a 4.4 percent growth in population (70,709 to 73,813).
The rate of growth within Caldwell County is slower than surrounding counties and the State of
North Carolina.
R-2237 NEPA/404 Merger Meeting 1-2 November 4, 1999
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1-1
Watauga County's population grew by 16.7 percent from 1980 to 1990 (31,666 to 36,952); a 10.2
percent increase in population is projected for the period 1990 to 2000 (36,952 to 40,726). The
census population figures do not represent the seasonal/part-year residents. Blowing Rock's
population rises to about 10,000 persons in the summer months, as estimated by Blowing Rock
town planners.
1.4.3 Project History
In 1993, an Environmental Assessment (EA) (NCDOT, August 1993) was prepared that
recommended widening US 321 from NC 268 in Patterson to US 221 in Blowing Rock. Based on
comments from the State Historic Preservation Officer and the general public, a Finding of No
Significant Impact (FONSI) (NCDOT, September 1994) was prepared for the southern 10.8 miles
of the project area, from NC 268 to SR 1500 (Blackberry Road). This section has independent
utility and its selection did not preclude consideration of alignments in the Blowing Rock area.
Because of the mountainous terrain, steep grades and poor alignment, improvements from NC
268 to SR 1500 are much needed from a safety and capacity standpoint. At public hearings,
representatives of government, businesses, Appalachian State University, and the public spoke
in favor of a four-lane US 321 between NC 268 and US 221. However, many citizens from
Blowing Rock strongly preferred a project that included a bypass around Blowing Rock. The
FONSI therefore indicated that an Environmental Impact Statement would be prepared for the
northern 4.3 miles of the EA's project area [from SR 1500 (Blackberry Road) to US 221 in Blowing
Rock] that compared the widening alternative with several Blowing Rock bypass alternatives.
1.5 THOROUGHFARE PLANNING
1.5.1 Overview of the Thoroughfare Planning Process
The thoroughfare planning process is a comprehensive transportation planning process that
integrates urban area planning practices with local, regional, and statewide transportation
planning practices. The process identifies transportation planning needs by evaluating land
development and population growth trends in rural counties and urbanized areas. The process
begins through a cooperative effort between the NCDOT's Statewide Planning Branch and local
planning officials. Socio-economic data is collected, including business and residential area
inventories, existing street inventories, identification of environmental constraints, and historical
information of the area. A base year transportation model is built. Utilizing input from local
planning officials, land development and population growth trends are projected and applied to
the model. Through this modeling process and local knowledge of the area's socio-economic
conditions, the thoroughfare planning team identifies transportation deficiencies and determines
short- and long-term solutions for eliminating or diminishing those deficiencies.
1.5.2 Caldwell and Watauga County Thoroughfare Planning
The 1981 Thoroughfare Plan prepared by the NCDOT for Caldwell County states that the number
of lanes should be increased from two to four on US 321. When identifying future road
improvement needs, the 1993 Thoroughfare Plan for Region D (Alleghany, Ashe, Avery, Mitchell,
Watauga, Wilkes, and Yancy Counties) assumes that US 321 is widened as specified in the
Transportation Improvement Program (see below). Watauga County adopted the Watauga
County component of the Region D plan.
R-2237 NEPA/404 Merger Meeting 1-4 November 4, 1999
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1.5.3 North Carolina Transportation Improvement Program
The project is included as TIP No. R-2237C in the 2000-2006 North Carolina Transportation
Improvement Program (NCDOT, 1999) covering the period from Federal Fiscal Year (FFY) 2000
to FFY 2006. Right-of-way acquisition and construction currently are not scheduled.
The following additional transportation improvement projects are near the project area:
R-2237A Widen US 321 to a multi-lane road from NC 268 at Patterson to SR 1370 (Nelson
Chapel Road) in Caldwell County. This project is under construction.
R-2237B Widen US 321 to a multi-lane road from SR 1370 (Nelson Chapel Road) to SR
1500 (Blackberry Road) in Caldwell County. Design is scheduled for FFY 2001,
right-of-way acquisition in FFY 2003, and construction in FFY 2005 or 2006.
R-529 Widen US 421 to a multi-lane road from NC 194 in Boone to two miles east of US
221 in Watauga County. This project is under construction.
U-3800 Widen to five lanes US 321 (Harden Street), Rivers Street (U-3406) to US 421/NC
194 in Boone. Design and right-of-way acquisition have started and construction
is scheduled for State FY 2000.
R-2566 Widen NC 105 to a multi-lane road from US 221 in Avery County to SR 1107 in
Boone. This project is identified as a future need only.
R-2615 Widen US 421 to a multi-lane road from US 221 in Boone to the Tennessee State
Line. This project is identified as a future need only.
1.6 TRANSPORTATION NETWORK AND OPERATING CHARACTERISITICS
1.6.1 Existing Road Network
US 321 is designated as a principal arterial in the statewide highway network and carries both
local and through traffic. It is a two-lane road within the project area and there is no control of
access. Other US routes in Watauga and northern Caldwell counties are US 421, which passes
east to north through Watauga County and Boone, and US 221, which passes southwest to
northeast through Watauga County via Blowing Rock and Boone. NC 105 and NC 194 also serve
Watauga county. 1-40 is the interstate highway nearest the project area, 40 miles southeast of
Blowing Rock at US 321's juncture with 1-40.
In the 1989 Highway Trust Fund Act, the North Carolina State legislature designated a network of
US and state highways as intrastate corridors. The Intrastate System was established to connect
major population centers and provide safe, convenient travel for motorists. The intrastate system
plan calls for the widening of the system's existing two-lane sections to at least four travel lanes.
US 321 from the South Carolina border south of Gastonia to its junction with US 421 west of
Boone, North Carolina is part of the Intrastate System. This corridor is defined as the principal
north-south route uniting the western Piedmont. US 421 is also a part of the Intrastate System.
R-2237 NEPA/404 Merger Meeting 1-5 November 4, 1999
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1.6.2 Roadway Characteristics and Posted Speeds
The roadway in the project area can be described best in three sections, each with common
characteristics:
The rural section south of Blowing Rock.
The urban section between Green Hill Road and US 321 Business in Blowing Rock.
The urban section between US 321 Business and US 221 in Blowing Rock.
The two-lane rural section south of Blowing Rock has a 22-foot paved travelway with a one-foot
paved shoulder on each side and a speed limit of 50 miles per hour (mph). The horizontal
alignment is poor with numerous sharp curves up to 30 degrees (design speed approximately 25
mph). In addition, the terrain is mountainous with nearly continuous grades between 6 and 8
percent uphill into Blowing Rock.
The two-lane urban section of US 321 between Green Hill Road and US 321 Business (which
passes through the Green Park Historic District) is approximately 0.8 mile long, with a 24-foot
pavement width and a travelway varying between 20 and 22 feet. The speed limit is 35 mph.
Grass shoulders are either non-existent or very narrow. The horizontal alignment is fair with a
series of four reverse curves up to 24 degrees (design speed approximately 30 mph). The
terrain is rolling with a maximum grade of 3.5 percent.
The 1.4-mile urban section between US 321 Business and US 221 has two lanes with a pavement
width varying between 20 and 22 feet and a speed limit of 35 mph. The northernmost 0.1 mile of
this section has four lanes. The alignment is generally straight on rolling terrain with a maximum
grade of five percent.
Passing opportunities along the entire project length are limited because of the terrain and sight
distance restrictions.
1.6.3 Sidewalks and Pedestrian Movements
There are no sidewalks along the project, except for a single existing sidewalk in front of the
Green Park Inn. Concentrations of pedestrian travel across US 321 occur at three points in
Blowing Rock -- Green Hill Road area, Sunset Drive, and Possum Hollow Road. In the Green Hill
Road area, pedestrians cross US 321 between the Green Park Inn and a parking lot opposite the
Inn.
1.6.4 Intersections and Access Control
The US 221, Sunset Drive, and Possum Hollow Road/Shoppes on the Parkway intersections, all in
Blowing Rock, are signalized. Traffic volumes on most intersecting roads are very light. No
restriction on access to abutting properties currently applies.
1.6.5 Traffic Volumes
Figure 1-2 and Table 1-1 show the 1998 Average Daily Traffic (ADT) for each major link on US
321 and the 2025 forecast ADT. The existing 1998 ADT was 7,525 vehicles south of Blowing
R-2237 NEPA/404 Merger Meeting 1-6 November 4, 1999
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Shoppes
on the
Parkway 29100
3,050
US 221
N 14,525
N 26,150
4,775
8,350
11,750
20,800
4,625
7,550
US 321
Business
2,425
5,300
A
15,350
27,450
12,275
21,600
11,875
21,200
Possum Hollow Road
625
750
Food Lion
1,275
2,200
12,300
21,300
Sunset Drive
1,125
10,000 1,600
17,400
%800
15,000
9,525
\16,900
8,975
15,900
8,925
15,900
15,150
/ Goforth Road
250
300
11175 Green Hill Road
2,000
325 7,525
450 141100 9,0
0\0
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Legend
1998 May Average Daily Traffic
2025 May Average Daily Traffic
Table 1-1
Existing (1998) and Forecast Average Daily Traffic (ADT)
and Forecast Peak Hour Volume
Link Maximum
2025 % Growth
1998 2025 (Peak 1998 to
Link Description (AD T) (AD T) Hour) 2025
South of Green Hill Road 7,525 14,100 1,970 87.4%
Green Hill Road-Goforth Road 8,925 15,900 2,230 78.2%
Goforth Road-US 321 Business 9,525 16,900 2,370 77.4%
US 321 Business-Sunset Drive 10,000 17,400 2,440 74.0%
Sunset Drive-Food Lion Driveway 12,300 21,300 2,980 73.2%
Food Lion Driveway-US 221 12,275 21,600 3,020 76.0%
US 221-Possum Hollow Road 15,350 27,450 3,840 78.8%
North of Possum Hollow Road 14,525 26,150 3,660 80.0%
Rock, 8,325 to 10,000 vehicles south of Sunset Drive in Blowing Rock, and 11,750 to 15,350
vehicles north of Sunset Drive. The 1998 ADT figures are extrapolated volumes calculated by the
NCDOT between its 1994 traffic counts and its 2025 forecasts. The original 1994 figures were
actual counts taken in May as a part of preparation of a new Boone thoroughfare plan. May was
chosen for the counts by the NCDOT after consultation with local officials and represents an
"average" month. The forecast traffic volumes for the design year 2025 are based on local
population and employment growth trends and the NCDOT's 1998 Blowing Rock Origin and
Destination Study.
The 2025 May ADT is forecast to be 14,100 vehicles south of Blowing Rock, 15,150 to 17,400
vehicles south of Sunset Drive in Blowing Rock, and 21,300 to 27,450 vehicles north of Sunset
Drive. Traffic is expected to grow between 73 and 87 percent between 1998 and 2025.
The traffic volumes include eight percent daily truck traffic on US 321, including three percent
tractor-trailers and five percent other trucks. Because non-truck traffic makes up a higher
percentage of total traffic during peak hours, the peak hour truck percentages are assumed to
be one-half of the daily percentage.
New or improved roads in North Carolina are designed to serve at an acceptable level of service
a "design hourly volume" or peak hour traffic volume 20 to 25 years in the future. This volume is
usually expressed as a percent of the ADT. For existing US 321 in 2025, the peak hour volume is
forecast to be 14 percent of the ADT. The 2025 peak hour volumes for each US 321 link are
shown in Table 1-1 and range between 1,970 and 3,840 vehicles per hour depending on the link.
1.6.6 Level of Service
Level of service (LOS) is a qualitative measure that characterizes the operational conditions
within a traffic stream and the perception of traffic service by motorists and passengers. The
different levels of service characterize these conditions in terms of such factors as speed and
travel time, freedom to maneuver, traffic interruptions, and comfort and convenience. Six levels
R-2237 NEPA/404 Merger Meeting 1-8 November 4, 1999

are used to measure level of service. They range from the letter A to F. For roadways, LOS A
indicates no congestion and LOS F represents more traffic demand than road capacity and
extreme delays.
Table 1-2 provides a general description of various level of service categories for roadways as
given in the 1994 Highway Capacity Manual, as well as descriptions for signalized and
unsignalized intersections. Specific level of service definitions vary for two-lane highways, multi-
lane highways, and intersections. In addition, the level of service for signalized and unsignalized
intersections cannot be compared directly. In general, a poor level of service rating still can be
considered acceptable for an unsignalized intersection. This is because the unsignalized
intersection analysis is based upon the availability of gaps in traffic for minor street traffic, which
means an intersection car, have a poor level of service despite no delays on the major street.
The signalized intersection analysis provides an overall average delay and level of service for the
entire intersection.
New or upgraded roads in rural areas in North Carolina typically are designed for LOS C for the
peak hour volume in the design year. This policy is based on pages 87 to 90 of A Policy on
Geometric Design of Highways and Streets (American Association of State Highway and
Transportation Officials, 1994). For urban areas, LOS D is typically acceptable when it is too
costly or environmentally damaging to design for a better level of service, but LOS C is preferred.
The goal for the US 321 improvements is LOS C or better in 2025.
Table 1.2
Level of Service Criteria

Level of
Service

Traffic Flow on Roadways Delay at
Signalized
Intersection Delay at Two-
Way Stop
Intersection
A Free flowing traffic with little or no delays <= 5 sec <=5 sec
B A stable flow with few congestion-related 5-15 sec 5-10 sec
restrictions on operating speed
C Stable flow but with more restrictions on speed 15-25 sec 10-20 sec
and changing lanes
D Approaches unstable conditions and passing 25-40 sec 20-30 sec
becomes extremely difficult. Motorists are delayed
an average of 75 percent of the time.
E The capacity of a roadway. Passing is virtually 40-60 sec 30-45 sec
impossible, speeds drop when slow vehicles or
other interruptions are encountered.
F Heavily congested flow with traffic demand >60 sec >45 sec
exceeding the capacity of the highway.
R-2237 NEPA/404 Merger Meeting 1-9 November 4, 1999

1998. Table 1-3 presents the design hour level of service for each roadway link. As shown, US
321 currently operates at LOS F south of Green Hill Road (and Blowing Rock). Since LOS F
reflects traffic volumes greater than the capacity of the road, it indicates high delays and
basically no passing opportunities exist during peak periods. A primary reason for this condition
is the mountainous terrain, which results in slow truck speeds. Through Blowing Rock, the level
of service is unacceptable (LOS D/E) in all locations, except north of the signalized intersection of
US 221. The better level of service north of Possum Hollow Road occurs because US 321 is four
lanes north of that point.
Table 1-4 summarizes the level of service for each intersection. All signalized and unsignalized
intersections currently operate at LOS C or better. However, a few of the side-street movements
at the unsignalized intersections are experiencing long delays (LOS F) during peak periods.
2025. Table 1-3 also includes level of service for forecast 2025 traffic. The road south of Blowing
Rock would continue to operate at LOS F in the peak periods although delays will increase
substantially. Operations on US 321 through Blowing Rock would operate at LOS E between
Green Hill Road and US 321 Business. Between US 321 Business and Possum Hollow Road, US
321 would operate at LOS F. Traffic flow under these conditions would be extremely congested
during peak periods.
The level of service at all existing signalized intersections on US 321 would deteriorate to
conditions worse than LOS F, as shown in Table 1-4. The level of service of the unsignalized
intersections at Green Hill Road, US 321 Business, and the Food Lion entrance also would
deteriorate to F. A planning level signal warrant analysis (using ADT and peak hour-based
warrants and the Institute of Transportation Engineers' (Kell and Fullerton, 1982) Manuaiof Traffic
Signa/Design, Second Edition) indicates the need for traffic signals at these intersections by
2025, although not as a part of an initial improvement, although for two of the three, through
traffic would continue to operate at LOS F.
Table 1.3
Design Hour Roadway Level of Service
Link Description 1998 2025
South of Green Hill Road F F
Green Hill Road-Goforth Road D E
Goforth Road-US 321 Business D E
US 321 Business-Sunset Drive D F
Sunset Drive-Food Lion Driveway E F
Food Lion Driveway-US 221 E F
US 221-Possom Hollow Road C F
North of Possom Hollow Road B C
R-2237 NEPA/404 Merger Meeting 1-10 November 4, 1999
Table 1-4
Peak Hour Intersection Level of Service
Intersection 1998 2025
US 321/Green Hill Road (Unsignalized) A (D) F (F*)
(Signalized) - F3
US 321/Goforth Road A (C) A (F)
US 321/US 321 Business (Unsignalized) A (F) F (F*)'
(Signalized) - D
US 321/Food Lion (Unsignalized) A (F)2 F (F*)2
(Signalized) - F3
US 321 /Sunset Drive (Signalized) C F"
US 321/US 221 (Signalized) B F*
US 321/Shoppes on the Parkway (Signalized) B F*
Notes:
All intersections are unsignalized unless indicated otherwise. For unsignalized intersections -"F
indicates the overall level for the intersection LOS; "(F)" indicates the worst movement LOS F* indicates
level of service worse than F and V/C (volume/capacity ratio) greater than 1.2.
'Signal may be warranted.
2Traffic signals on either side of this intersection create large gaps. This may result in better levels of
service in reality than the levels of service analysis indicates.
3US 321 through traffic would operate at level of service F
1.6.7 Accidents/Safety
Accident data for the project area were assessed for the period between June 1, 1996 and April
30, 1999. Accident rates, categorized by fatal accidents, non-fatal injury accidents, property
damage accidents, and total number of reported accidents, were compared to average rates for
other roads with similar characteristics in North Carolina. Average crash rates for various roads
in North Carolina are also based on NCDOT data for the years 1996 through 1998.
The accident rates are summarized as accidents per 100 million vehicle-miles driven. For
example, if a 10-mile section of road carries an average of 10,000 vehicles per day, in one year
36.5 million vehicles-miles of travel would occur on that 10-mile stretch of road (10 miles times
10,000 vehicles per daytimes 365 days per year). If five accidents occur on this 10-mile section
of road in a three-year period the accident rate is 4.6 accidents per 100 million vehicle miles.
The 4.6 accidents per 100 million vehicle-miles assumes that over the three-year period 109.5
million vehicle-miles of travel occur (36.5 million times 3) and five accidents. The 4.6 is
calculated by dividing 100 million vehicle-miles by 109.5 million and multiplying the result by 5).
If one were interested in the average number of accidents per year, one would divide 5 by 3 for
and average of 1.7 accidents per year.
Table 1-5 shows the number of accidents from 1996 to 1999 and accident rates for the existing
roadway compared with the average rates for similar US routes in North Carolina.
R-2237 NEPA/404 Merger Meeting 1-11 November 4, 1999
Table 1-5
Accident Rates'
Accident Rate
Number of NCD07-3
Accidents on A verage for
US 321(1996 Existingo 2 Lanes Percent
Accident Type to 1999) US 321 Undivided Difference
Rural Section South - Blackberry Road (SR 1500) to Blowing Rock Town Limits
Fatal 0 0* 2.60 N/A*
Non-Fatal 9 67.69 88.37 -23%
Property Damage Only 16 120.34 102.96 17%
Total 25 188.03 193.93 3%
Urban Section - Town Limits (south) to Town Limits (north of Possum Hollow Road)
Fatal 1 4.01" 1.10 N/A*
Non-Fatal 37 148.32 120.35 23%
Property Damage Only 55 220.48 169.39 30%
Total 93 372.82 290.84 28%
'Rates based upon 100 million vehicle mile exposure
2NCDOT accident data 6/1/96 through 4/30/99
3Average rates provided by NCDOT for rural and urban two-lane US routes for 1996-1998
*Accident rate resulting from zero or one fatality and is not statistically significant
Rural Section
The rural portion of US 321 starts at SR 1500 (Blackberry Road) and ends at the Blowing Rock
town limits, 0.2 miles south of the intersection with Green Hill Road. It has a total length of 1.8
miles. As indicated in Table 1-5, the accident rate for the rural portion is comparable to the state
average for a rural roadway with similar characteristics. The rural portion of US 321 has a 23
percent lower non-fatal injury rate than the state as a whole, although the property damage only
accident rate is 17 percent higher, resulting in a similar overall rate with lower severity. There
were no reported fatal accidents during the reported period in this portion of US 321.
The majority of the accidents on the rural section were comprised of a few general types. Forty-
eight percent of the accidents involved single vehicles running off the road. In addition, 24
percent of the accidents were the result of vehicles striking the rear of a slower or stopped
vehicle and 20 percent were angle accidents. The provision of extra lanes and standard
shoulders could reduce these accidents substantially. Easing of the sharp curves could result in
fewer vehicles running off the road and improve visibility to decrease rear-end accidents.
While weather plays a factor in some accidents, no specific trends were noted in the accident
analysis. No data were available to measure the effect of fog on accidents.
Urban Section
The urban section of US 321 is a 2.3-mile route through the Town of Blowing Rock. It starts at the
town limits, just south of Green Hill Road, and ends just north of Possum Hollow Road. The
existing accident rates in the urban section are presented and compared with North Carolina
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I
averages in Table 1-5. The total accident rate for existing US 321 through Blowing Rock is 28
percent higher than similar urban US routes in North Carolina. The non-fatal injury accident rate
is 23 percent higher and the property damage accident rate is 30 percent higher than the state
comparative rate.
One fatality did occur during the three year period. A high fatality rate resulted from only one
fatality because of the low exposure for the three-year accident study period. It takes more than
three years for 100 million miles of travel to occur on this segment of US 321 and the number of
fatal accidents in North Carolina is far lower than for other types of accidents. Thus, the
differences between Blowing Rock's three-year record of one fatality and the statewide averages
for the same period are not statistically significant. The high accident rate overall and the high
rates for the other two more common types of accidents, however, are indicative of a road that is
not as safe as it could be.
Accident records indicate that almost all intersections on this section of US 321 are prone to a
high number of accidents. A majority of these accidents, 48 percent of the total, involved
vehicles rear-ending slow or stopped vehicles. An additional 24 percent involved angle
collisions. Between US 321 Business and US 221 on the northern end of this section, accidents
often were related to traffic entering/exiting driveways. No weather-related trends were observed
in the urban section.
The analysis identified five specific high accident locations. Of the five locations identified, four
were individual intersections. The single roadway section identified includes a series of reverse
curves (curve in one direction that is followed almost immediately by a curve in the opposite
direction), as well as two closely spaced intersections with poor sight distance. The locations
are:
• Green Hill Road intersection - 6 total accidents, 5 injuries
• Road section that includes intersections with Pinnacle Avenue and Country Club Road -- 10
total accidents, 8 injuries, and 1 fatality.
• US 321 Business intersection -- 18 total accidents, 9 injuries.
• Sunset Drive signalized intersection -- 16 total accidents, 2 injuries.
• Possum Hollow Road/Shoppes on the Parkway signalized intersection -- 18 total accidents,
12 injuries.
1.7 MODAL INTERRELATIONSHIPS
The project area is not served by rail. An airport is in Boone. There is no relationship between
the proposed project and the airport in Boone.
1.8 SUMMARY
The proposed improvement is included in county thoroughfare plans and the NCDOT's 2000 to
2006 Transportation Improvement Plan. Without the proposed action, the forecast traffic along
this section of US 321 will exceed the road's capacity, creating undesirable levels of service.
Improvements are needed to provide congestion relief. In addition, without improvement, high
accident rates are expected to continue. The number of accidents will likely rise as traffic
volumes continue to rise. Improved sight distances can be created by straightening curves and
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by providing separate lanes for drivers turning left or providing with an additional through lane an
opportunity for through traffic to pass those turning.
This portion of US 321 is part of the North Carolina Intrastate System. The US 321 corridor is
defined as the principal north-south route uniting the western Piedmont.
The proposed project is a reasonable expenditure of public funds even if no additional
improvements are made.
2. REFERENCES
American Association of State Highway and Transportation Officials. 1994. A Policyon
Geometric Design of Highways and Streets American Association of State Highway and
Transportation Officials, Washington, DC.
Kell, J. H. and I.J. Fullerton. 1982. Manual of Traffic Signal Design, Second Edition. Institute of
Transportation Engineers, Washington, DC.
North Carolina Department of Transportation. August 1993. Administrative Action Environmental
Assessment and Draft Section 4(f) Evaluation. Prepared by Parsons Brinckerhoff Quade
& Douglas, Inc. in association with Wapora, Inc.
North Carolina Department of Transportation. September 1994. Administrative Action Finding of
No Significant Impact. Prepared by Parsons Brinckerhoff Quade & Douglas, Inc.
North Carolina Department of Transportation. 1981. Caldwell County Thoroughfare Plan.
North Carolina Department of Transportation. 1993. Region D Thoroughfare Plan (Alleghany,
Ashe, Avery, Mitchell, Watauga, Wilkes, and Yancy Counties).
North Carolina Department of Transportation. 1999. Transportation Improvement Program 2000-
2006.
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