Morrisville Transportation Plan - 2009

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40 6 Design Guidance
Figure 6.2 Additional Bicycle Facility Design
(A) Generally, the multi-use trail, sometimes called a “sidepath” as shown in (B), is difficult
to design on streets that have a large number of driveway and/or street intersections due
to conflicts with turning vehicles and the additional threat posed by cyclists riding against
traffic in the near vehicular travel lane. The risks can be minimized by moving the multi-use
trail at least 10’ off the near travel lane, and bringing it back to the intersection for street
crossings (bottom). Otherwise, a mid-block crossing may be warranted for crossings with
large numbers of pedestrians and cyclists crossing (greater than 20 in the peak hour, for
example). Mid-block crossing safety is improved when pedestrian-activated signals are
used along with clearly visible stop bars and crossing markings.
(B) The City of Charlotte, examining pedestrian safety factors, considers the factors shown
in this diagram as an initial screening of when to install mid-block crossing devices for multi-
use and pedestrian crossings. Taken together, these factors comprise a “solution space”
where mid-block crossing treatments are recommended, then further studied to deter-
mine which specific treatment is used.
Figure 6.2 (A)
Figure 6.2 (B)
6.1 Bicycle and Pedestrian Design Guidance, cont’d
only in circumstances where a 10’ minimum is impractical due
to specific site conditions.
6. Modify the existing subdivision ordinance to specify a maxi-
mum block length of 600 feet (450 feet in Town Center Area
and Activity Centers) except where it is not practicable as
determined by the Town Engineer.
7. During construction, enforce the recommendations con-
tained in the Manual on Uniform Traffic Control Devices to
provide pedestrian and bicycle detours where sidewalks and/
or bicycle facilities are blocked temporarily.
8. Off-site pedestrian and bicycle improvements are warranted
in the near vicinity of a major pedestrian or bicycle trip gener-
ator in the same way that off-site improvements to vehicular
trafficarewarranted if thedevelopment negatively affects the
level-of-service of existing roadways. Importantly, there must
be a clear and causal connection between the need for any
off-site improvement and the proposed development; a de-
veloper cannot, for instance, be required to repair an existing
deficiency in the system that s/he is not aggravating through
the increased demand presented by the proposed develop-
ment action. Therefore, it is hereby recommended that the
Town of Morrisville amend the current subdivision and zon-
ing ordinances to include mandatory pedestrian (including
off-street greenway) and bicycle connections within ¼-mile
of a new / retrofitted development when all of the following
conditions exist, except as determined not practicable by the
Town Engineer:
• Public right-of-way is available to make a currently non-ex-
isting connection to an existing or approved pedestrian / bi-
cycle facility; AND
• The proposed new / retrofitted development is expected to
generate 250 or more trips per day according to the latest
edition of the ITE Trip Generation Manual.
Additional Guidance and Resources
AASHTO, Guide for the Development of Bicycle Facilities (website:
www.sccrtc.org/bikes/AASHTO_1999_BikeBook.pdf). Note: Update of
the 1999 edition forthcoming at the time of this writing.
Institute of Transportation Engineers, Design and Safety of Pedestrian
Facilities, A Recommended Practice, 1998.
Federal Highway Administration, Designing Sidewalks and Trails for
Access, Part II of II: Best Practices Design Guide, 1999.
Federal Highway Administration / Project for Public Spaces, Context
Sensitive Solutions (website: .
Accommodating Bicycle and Pedestrian Travel: A Recommended
Approach, A US DOT Policy Statement Integrating Bicycling and
Walking into Transportation Infrastructure, Design Guidance (website:
www.fhwa.dot.gov/environment/bikeped/design.htm#d5 ).
Town of Morrisville Subdivision Ordinance v.8.0 and Zoning Ordinance
v.8.0(www.ci.morrisville.nc.us/planning/downloads.asp).
Charlotte, North Carolina, Urban Street Design Guidelines
(website: www.charmeck.org/Departments/Transportation/
Urban+Street+Design+Guidelines.htm).
The Louis Berger Group, Inc., City of Durham DurhamWalks! Pedes-
trian Plan. 2006.
Wisconsin Department of Transportation, Bicycle Facility Handbook,
January, 2004.
Federal Highway Administration, Manual on Uniform Traffic Control
Devices (website: .