Page 8 - July-Aug2020 Vol38 No2

West Walnut Street from page 7
awareness of each other – cars to bicycles, bicyclist (and prevent a stop condition) as
bicycles to pedestrians, and so on. One
aspect to note is that Walnut Street does
not have a stop condition at any of its
side street intersections. We continued
the “no-stop” condition on Walnut Street
over to the cycle track to increase the
functionality of this facility. Four major
methods were employed throughout the
corridor to increase safety and awareness.
1. Pavement colors and patterns:
specifically, permanent pavement
markings and brick pavers provide
better visibility, all contrasting with the and bike lanes. To ensure appropriate
black asphalt. These include the green
bicycle lane markings at all intersections
(including driveways), dark red brick
pavers within crosswalks, light brick
pavers interior to the intersection, and
plain concrete ramps leading up to the
raised intersections and banded to the
crosswalks.
2. For signing, a combination of
conventional and custom sign panels was
used. Two examples of the conventional
signs used are the W11-2 “pedestrian
crossing” to warn motorists of crosswalks
and the R9-6 “bikes yield to peds” to
warn bicyclists of crosswalks. A custom
8 TPW July/August 2020
sign assembly “turning vehicles yield to
bike lane” was required to protect the
they move through the intersection. The
custom assembly is based on a photo in
the Urban Bikeway Design Guide, which
was taken in Arizona.
3. Lighting for the roadways, bike
lanes, and sidewalks was a key safety
component that Johnson City staff wanted
to emphasize in the design. Two types of
poles were utilized, one with a 20' fixture
mounting height for roadway lighting,
and the other with a 14' mounting height
to fill in the dark gaps on sidewalks
light levels were obtained, photometric
calculations were performed to determine
the theoretical light levels throughout the
corridor based on our proposed layout
and fixture design. The average spacing
for the taller 20' poles was roughly 100
feet, on alternating sides of the road, and
the spacing for the 14' poles was about 60
feet. The style of the proposed light poles
and fixtures was based on historical train
station photos which will give a unique
look to the corridor and reflect on the
City’s historically significant rail-system. improve their community and have
4. Traffic Calming throughout the
project was accomplished by four methods.
• The proposed raised intersections are
elevated four inches above the adjacent
grade and include concrete ramps and
white triangular speed hump pavement
markings.
• Chicanes at intersections – 18-degree
reverse curves with an 8' horizontal
alignment offset.
• Reduction of the travel lane width
from 13.5 feet to 10 feet. “Travel lane
widths of 10 feet generally provide
adequate safety in urban settings while
discouraging speeding.” - NACTO
Urban Street Design Guide
• Reduction of the posted speed limit from
30 mph to 25 mph, which complements
the other three measures listed above.
This project has been special to work
on so far due to the commitment to
teamwork, sense of project ownership,
and shared responsibility that LDA has
seen come from within the community
over the life of the project. Johnson City
citizens have witnessed first-hand how
strong Public Works projects can greatly
proven themselves invaluable engineering
partners. LDA looks forward to the final
stages of the design process of this project
and anticipates the project will break
ground in the Summer of 2021.