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3
Existing Conditions
3.0 E
xisting
C
onditions
3.1 Roadways
The people of Morrisville live in a place that many other people are going through on the
way to someplace else: Research Triangle Park, Raleigh-Durham International Airport, and
the municipalities of Raleigh, Cary, and Durham. This statement was particularly true until
the turn of the millennium, when the night-time, residential population of the Town started
to catch up with the day-time, employee population. Many of these new residents are
accommodated in residential subdivisions that exemplify disconnected development pat-
terns. Figure 3.1 compares the suburban land use and transportation pattern of Morrisville
to the more connected patterns of other cities. Morrisville’s development is the product
of rural heritage and suburban location. However, it has the option of development pat-
terns that are more connected, which could allow for shorter trips between work, home
and shopping.
The impact of the suburban development pattern is to funnel nearly all trips onto a few
major (arterial) roads. Combined with Morrisville’s rapid development and the fact that
more than 90% of all trips in Morrisville are made by private automobile (the vast majority
with just one person in the car), this pattern has led to substantial traffic congestion and
delays. Moreover, the Triangle Region’s municipalities, including Morrisville, perennially
exceed Environmental Protection Agency (EPA) limits for major air quality pollutants like
ozone, partially due to the reliance on private automobile travel.
Level of Service
Traffic specialists and engineers typically measure transportation performance in two
ways: traveler delay (especially during “peak” morning and evening rush periods) and
the number of traffic accidents. Figure 3.2 illustrates recent data for the former. Note that
the Level-of-Service letter codes are simply a shorthand way of discussing traffic in terms
of traveler delays. Like a grade received in school, ‘A’ is great, indicating that
the vehicle traffic is within the roadway capacity and flows freely, but ‘F’ is bad,
indicating that vehicle traffic greatly exceeds the design capacity for that road,
leading to significant delays (Figure 3.3 below provides more detail). The grades
are given based on the
worst
conditions on a roadway, during peak times, and
can be different for different directions (e.g., northbound is rated ‘A’ but south-
bound is rated ‘C’). These reflect current conditions as of spring 2008, with ongo-
ing widening projects unaccounted for.
Figure 3.3 Basic Level-of-Service (LOS) Descriptions
LOS
Car
Bike
3
Pedestrian
4
Example Morrisville
Locations
Street
1
Intersection
2
A >80%
<10
<10
<10
Eastbound ramp to NC
540 from NC 54
B 65-80
10-20
10 - 20
10 - 20 Town Hall Drive
C 50-65
20-35
20 – 30 20 – 30 Eastbound Aviation
Parkway
D 40-50
35-55
30 – 40 30 – 40 Perimeter Park Drive at
Airport Boulevard
E 25-40
55-80
40 – 60 40 – 60 Morrisville Parkway at
NC 54
F
<25
>80
>60
>60
Aviation Parkway at NC
54
(1) Percent of free-flow vehicle speed on road. E.g., if the speed you drive in free-
flowing traffic (no delays) is 45 mph, then the roadway receives an ‘A’ if the speed
at peak times is greater than 36 mph (80%).
(2) Intersection delay, in seconds.
(3) Bicycle delay at intersection, in seconds.
(4) Pedestrian delay at intersection, in seconds.
Figure 3.1 Example Land Use and
Transportation Patterns
A. (above) Photos and graphics illustrate the different
land use patterns of cities. Note the connected patterns
of both Boston and Portland, characteristic of older
cities. More recent forms are less planned and more
focused on separating land uses from each other.
B. (below) Diagrams compare Connected and
Separated land use and transportation patterns.
These patterns have implications for development
costs, traffic congestion, and the ability to travel
to basic needs by car, foot, transit, or bicycle.
Connected
Separated